Origination and diversification of Devonian ambocoelioid brachiopods in South China
The superfamily Ambocoelioidea is an important group of the Brachiopoda in the Devonian, both globally and in South China. In the Devonian, this group is also most diverse compared with that in other periods. Based on features of cardinal process and cruralium, three types of cardinalia are recognised, including Ambocoelia-type, Emanuella-type, and Rhyncospirifer-type. Our study shows that the Rhynchospirifer-type cardinalia is a distinct character that distinguishes them from the rest of the Ambocoeliidae; therefore, the Rhynchospiriferinae is re-elevated to the family rank. Guangxiispirifer of the previous Ambocoeliinae is reassigned to the Rhynchospiriferidae while Ambothyris, Choperella, Crurispina, Diazoma, Emanuella, Ilmenia, Ilmospirifer, Ladjia, Moravilla, and Zhonghuacoelia of the previous Rhynchospiriferinae are transferred to the Ambocoeliidae (= previous Ambocoeliinae). Three earliest ambocoelioids in South China are Ambothyris, Amboglossa, and Prolazutkinia in the upper Emsian; their emergences were likely associated with the global Upper Zlichov Event. The upper Emsian occurrences of Amboglossa and Prolazutkinia are their FADs (first appearance datum) globally. These two genera probably gave rise to the Rhynchospiriferidae and the Lazutkiniidae, respectively. After an initial gradual increase in generic richness, the Ambocoelioidea reached the highest diversity (10 genera including four endemic genera) in the late Eifelian and Early Givetian in South China. From then on, the diversity gradually decreased till the end of the Devonian (two genera) and was least affected by the Frasnian–Famennian Event. The Ambocoelioidea is a strongly facies-controlled group. Their temporal and spatial distributions show a close relationship with sea level changes. Ambocoeliids and rhynchospiriferids were adapted to different environments. The former inhabited deeper and partly dysoxic environments, therefore showed greater capabilities to migrate and survive extinctions. On the other hand, the rhynchospiriferids dwelled in a reef-related, high energy, and oxic environments, which were probably more sensitive to environmental changes; they also showed high diversity and endemism and more easily experienced rapid and regional extinctions. Three species representing the three types of cardinalia, Ambocoelia yidadeensis sp. nov., Ambothyris panxiensis, and Rhynchospirifer sp., are described.
KeywordsDevonian Brachiopods Ambocoelioidea Rhynchospiriferinae Classification Diversity South China
Brachiopods were very abundant in the Devonian of South China, which play an important role in stratigraphic divisions, correlations, and palaeoenvironmental reconstruction. Because of this, brachiopod studies may be traced back to one and a half centuries ago, from morphological description (e.g. Davidson 1853) to modern comprehensive studies of morphology, stratigraphy, palaeogeography, ancient environments, evolution, and diversity change (e.g. Hou and Xian 1964; Jin 1988; Chen 1984; Chen and Yao 1999; Ma 1995, 2009; Ma and Day 2003, 2007; Ma et al. 2006) over.
The Ambocoelioidea is a major group in the Upper Palaeozoic, of which the family Ambocoeliidae accounts for 80% of the total 45 genera (data based on Johnson et al. 2006 and Gourvennec and Carter 2007). The Devonian saw the radiation of the superfamily, with the four families (Ambocoeliidae George, 1931, Lazutkiniidae Johnson and Hou, 1994, Eudoxinidae Nalivkin, 1979, and Verneuiliidae Schuchert, 1929) all present at various times. The Devonian is also the period during which this group is most diverse, with 34 out of 45 genera in the history of the Ambocoelioidea; the Rhynchospiriferinae of the Ambocoeliidae are even exclusively restricted to the Devonian. In South China, the Ambocoeliinae are also abundant. This paper focuses on the origin and diversification of the Ambocoeliidae in South China, with discussions on a new classification scheme of the family.
In the following text, formal Givetian and Frasnian substage divisions are consistent with the scheme approved by the Subcommission on Devonian Stratigraphy (SDS) (Becker 2007; Becker et al. 2012), with base of Po. rhenanus/Po. varcus Zone, base of (Lower) Schmidtognathus hermanni Zone, base of the Pa. punctata Zone, and approx. base of the Lower Pa. rhenana Zone as the base of the Middle Givetian, Upper Givetian, Middle Frasnian, and Upper Frasnian, respectively. The Emsian substages follow the suggestion of SDS, with the base of the Po. inversus Zone as the lower–upper Emsian substage boundary. For convenience, the Eifelian is temporarily divided into lower and upper Eifelian at the start of the Haikou Uplifting, approximately at the upper Tortodus kock. australis to lower Tortodus kock. kockelianus zones (Ma et al. 2017); the four informal Famennian substages are only broadly correlated with the conodont zonation, with base of the Lower Pa. rhomboidea Zone, base of the Lower Pa. ru. trachytera Zone, and base of the Middle Pa. gr. expansa Zone as the base of the middle, upper, and uppermost Famennian, respectively. Abbreviations used in this paper are: Pa. = Palmatolepis, Po. = Polygnathus, Fm. = Formation; Mbr = Member; for abbreviation of brachiopod generic names, see Appendix.
Under the abovementioned palaeogeographic framework, four major basic facies types may be recognised in South China (Xian et al. in Hou and Wang 1988). The Xiangzhou type (subtidal benthic facies) is characterised by shallow, well-oxygenated, and agitated water environments with abundant various benthic organisms; the Nandan type (pelagic facies) occupied the platform basin areas (Fig. 1) and is characterised by predominant pelagic fossils and minor thin-shelled brachiopods; the Transitional type (mixed benthic and pelagic facies) represents a platform marginal facies between platforms and platform basins with alternating deeper and shallow water sediments; and the Qujing type (littoral facies) is characterised by intertidal clastic deposits with fish, vascular plants, and spores. The ambocoelioid brachiopods can be found in a variety of environments, but they mostly inhabited deeper water areas, including deeper subtidal and platform basin (rift-basin) environments; however, the Rhynchospiriferinae seem to prefer a platform setting.
Temporal and spatial distributions of the Ambocoelioidea
No ambocoelioids have been found in the Silurian in South China yet although there were favourable sedimentary rocks that yield various other brachiopod taxa. The upper Ludlow Guandi (= Kuanti) Fm. and Miaogao (= Miaokao) Fm. (especially the latter) yield various brachiopods including orthides, rhynchonellides, atrypides, athyridides, and spiriferides (without ambocoelioids) in eastern Yunnan (Qujing) (Zhang et al. 1996); the Pridoli Yanglugou Fm. (= upper Bailongjiang Fm.) of western Qinling bears relatively abundant and diverse brachiopods, including the spiriferide cyrtioids (Eospirifer and Hedeina of the Cyrtiidae), adolfioids (Nikiforovaena of the Adolfiidae), delthyridoids, and reticularioids as well as other brachiopods (Rong et al. in XIGMR and NIGP 1987); the Wenlock Zhoushan Group (including the Xiaolianggou and Miaogou formations; limestones and metamorphosed clastics) yields various brachiopods including rhynchonellides and athyridides, and the Pridoli(?) Bailongjiang Group (metamorphosed limestones and clastics) yields corals and brachiopods (atrypides, orthides, spiriferides, and others and conodonts, trilobites) (GBDMR 1989). Zhang (in XIGMR and NIGP 1987, vol. II, p. 133–134) mentioned that Amboglossa mosolensis ranges from the Pridoli Yanglugou Fm. to the Upper Givetian–Lower Frasnian Pulai Fm., but only the upper Emsian–lower Eifelian Dangduo Fm. and upper Eifelian Lure Fm. and basal Xiawuna Fm. can be confirmed that yield the species (with an Amboglossa sp. in the lower Givetian Xiawuna Fm.).
In the Devonian, the Ambocoelioidea is very abundant. According to Johnson et al. (2006) and Gourvennec and Carter (2007), there are 45 genera in total in the superfamily (Fig. 2), of which the Ambocoeliidae include 36 genera, accounting for 80%; the Lazutkiniidae, 2 genera; the Eudoxinidae, 4 genera, and the Verneuiliidae, 3 genera. Thirty-four genera (76% of the total ambocoelioid genera) lived in the Devonian, including 29 genera of the Ambocoeliidae (accounting for 85% of the total Devonian genera), 2 genera of the Lazutkiniidae, 1 genus of the Eudoxinidae, and 2 genera of the Verneuiliidae. Of the Devonian genera, 60% (27 genera) were present in the Middle Devonian, reaching the highest diversity in generic richness and widest geographic distributions (Figs. 2 and 3). The Rhynchospiriferinae and the Lazutkiniidae are restricted to the Devonian, with numerous endemic taxa in South China (Fig. 3: genus Nos. 27–29), making the South China region an important area for the study of this superfamily.
During the Early Devonian Lochkovian through Pragian, the Ambocoelioidea were most diverse in the Euramerica continent. They did not occur in South China until the late Early Devonian (Emsian) although brachiopods are relatively diverse from the Lochkovian through Pragian in the Yulin area of Guangxi, a facies characterised by deeper water clastics with alternating brachiopod and graptolite faunas (Wang and Yang 1998) including various spiriferides: Hedeina (Eospiriferinae, Cyrtioidea), Nikiforovaena of the Adolfiidae (Adolfioidea), Orientospirifer of the Delthyrididae (Delthyridoidea), Quadrithyrina and Quadrithyris of the Xenomartiniidae, and Reticulariopsis of the Reticulariidae (both Reticularioidea) as well as other brachiopods. In the Middle Devonian, the Ambocoelioidea were most diverse in the whole world, especially in the Euramerica continent and South China. During the Late Devonian, this group started to decrease in diversity, with a limited number of genera recorded in the Lower Frasnian (Veevers 1959a; Beus 1965; Mottequin 2008; Ma 2009; Baliński et al. 2016). The Frasnian–Famennian Mass Extinction Event does not seem to significantly affect the group (Fig. 2) as they were already very rare in the Frasnian. In the Carboniferous and Permian, the diversity kept on a low level until finally becoming extinct in the Early Triassic (Fig. 2).
Ambocoelioid distribution in South China
Stratigraphy and divisions
In the absence of pelagic index fossils, benthic coral and brachiopod faunas may also play an important role in the correlation (e.g. Ma et al. 2009a). The regional Yujiangian (lower Emsian) is characterised by the Dicoelostrophia–Rostrospirifer tonkinensis Assemblage in the Tonggeng, Yujiang, and Ganxi formations of various sections. During the Ertangian (mid-Emsian, approx. the conodont Eocostapolygnathus nothoperbonus Zone; Hou et al. 2017), the Moding deepening/rifting event happened, which probably resulted in the wide spread of the ammonoid Erbenoceras fauna in South China, e.g. in the Dale and Nandan sections (Ma et al. 2009a). The Sipaian (upper Emsian) is characterised by the Trigonospirifer trigonata–Otospirifer daleensis–Euryspirifer paradoxus Assemblage which is widely distributed.
The lower Eifelian is characterised by the brachiopod Athyrisina–Yingtangella–Xenospirifer Assemblage Zone and the coral Utaratuia Assemblage. Some major elements of the assemblage such as Eospiriferina houershanensis subplanus and Athyrisina squamosa can also be found in the equivalent strata in the West Qinling region. In South China, the late Eifelian saw a general sea level fall (Haikou Movement of Hou 1978) as represented by the Changcun, Dahekou, and Tunshang members, and lower Jinbaoshi Fm. (Fig. 4).
The Stringocephalus Abundance Zone bears various terebratulide, spiriferide, and atrypide brachiopods, which spans the Lower and Middle Givetian times (Ma and Zong 2010). The Jide, Dushan, Yijiawan, Qiziqiao, Poxi, Qujing, upper Jinbaoshi, lower and middle Guanwushan, and Xiawuna formations yield various brachiopods of this zone. Within this zone, the coral Endophyllum is also wide spread, representing the Endophyllum transgression in South China (Liao and Ma 2011) approx. at the end of the Early Givetian. In the Upper Givetian, Stringocephalus was very rare; instead, ambocoeliids and leiorhynchids became relatively abundant. The base of the Upper Givetian in South China is characterised by a sharp lithological change (deposits resulting from a sea level rise) in a number of sections such as the Panxi section, Longmenshan, and Tewo sections. There are a few sections where the Upper Givetian deposits may be missing probably due to erosion during an assumed subsequent regression (Ma et al. 2017) such as the Dushan, Qiziqiao, and Xikuangshan sections (Liao et al. 1979; Wang et al. 1986).
Brachiopods of the Lower Frasnian in South China are similar in composition to those of the Upper Givetian; both intervals belong to the ambocoeliid-leiorhynchid Assemblage Zone of Ma and Zong (2010). However, the ambocoeliids Diazoma and Emanuella, and rare Stringocephalus may be found in the Upper Givetian, whereas the leiorhynchids Leiorhynchus, Calvinaria, and Yocrarhynchus are only found in the Frasnian (Zhang et al. 2015). In the Middle Frasnian, the emergence of the Cyrtospiriferidae and the Conispiriferidae in South China was approx. in the Pa. hassi Zone (Ma et al. 2006). The lower part of the Upper Frasnian is characterised by the flourishing of reefs and reefal carbonates at the Qilijiang highstand of Ma et al. (2017) and subsequent drowning of reefs due to a sea level rise (Lower Kellwasser Event) (Ma et al. 2016). All the above faunal and sea level change events may serve to make stratigraphic correlations.
The lower and middle Famennian (= local Xikuangshanian stage) are characterised by the Yunnanella (previously Yunnanellina)–Sinospirifer and Nayunnella (previously Yunnanella)–Hunanospirifer Assemblage Zones, respectively, which are readily recognised and differentiated by their taxonomic differences (Ma and Zong 2010). Probably due to an interpreted sustained sea level fall/lowstand in the early Famennian, deposits of the Yunnanella–Sinospirifer Assemblage Zone may be missing in many then coastal areas in central Hunan (Ma and Zong 2010). The Yangshuoan is represented by deposits (coarse clastics and dolostone) under a regressive phase in the isolated platform and nearshore areas. Benthic fossils are very rare in this interval in various pelagic and neritic sections so that no coral and brachiopod assemblages can be established (Ma et al. 2009a). The Shaodongian represents a renewed marine transgression (e.g. Ma et al. 2017). Subsequently, the corals Cystophrentis and/or Beichuanophyllum became widely distributed in South China in the interval approx. equivalent to the Etroeungt of Europe, commonly associated with the last cyrtospiriferids.
Stratigraphic and geographic distribution of the ambocoelioids
Ambocoelioid brachiopods mostly occur in Xiangzhou, Liujing, Nandan, and Nanbiancun of Guangxi, Dushan of Guizhou, Panxi and Qujing of Yunnan, Xikuangshan, Shetianqiao, and Ningxiang of central Hunan, Longmenshan of Sichuan, and Tewo of Gansu (see Fig. 1 for locations and Fig. 4 for stratigraphic correlation) (see Appendix for a full taxonomic list of the Ambocoelioidea in South China and their revised names).
The Dushan section of Guizhou is also of a typical shallow water platform facies, with ambocoelioid brachiopods in various horizons (Liao et al. 1978; Xian and Jiang 1978; Wang and Zhu 1979; Ma et al. 2009a; this study). The lower Eifelian Longdongshui Fm. yields Amboglossa and Guangxiispirifer. The upper Eifelian Tunshang Mbr of the Bangzhai Fm. yields Levibiseptum (the Dahekou Mbr lacks fossils according to Liao et al. 1978). The Lower Givetian Jipao Mbr of the Dushan Fm. bears Rhynchospirifer. The basal Jiwozhai Mbr of the Dushan Fm. yields the coral Endophyllum, which indicates that the level still lies in the Lower Givetian (Hou et al. 1988; Liao and Ma 2011) and that the rest of the Jiwozhai Mbr is of Middle Givetian age with Ladjia and Diazoma. The Lower Frasnian basal Hejiazhai Mbr of the Wangchengpo Fm. yields Ambothyris and Ladjia (including Emanuella torrida and Em. takwanensis in Ma 2009, Crurithyris jiwozhaiensis in Wang et al. 1974).
In central Hunan, the Middle and Upper Givetian “Yijiawa Fm.” of the Shetianqiao section yields Emanuella (Ma et al. 2004); the Middle Givetian Qiziqiao Fm. in the Ningxiang area bears Zhonghuacoelia sinensis (= Ambocoelia sinensis in Tien 1938); the uppermost Famennian Menggong’ao Fm. in the Xikuangshan section yields Crurithyris (own data), a brachiopod that is distinct in the cardinalia (see the next section for discussion).
The Liujing area of Guangxi, an important reference section for correlation of different facies, is characterised by deposits of a platform–“basin” transitional facies, with both benthic and pelagic fossils. Brachiopods of the Mintang Fm. have been studied in detail by Xian (1983, 1998), Sun (1992), and Baliński and Sun (2016), including Ambocoelia, “Moravilla” (our quotation marks), Changtangella, Guangxiispirifer, Ilmenispina, Cyrtinoides, and Rhynchospirifer in the Eifelian part (basal Mintang Fm.) and Changtangella, Guangxiispirifer, Rhynchospirifer, and Ilmeniopsis in the Lower Givetian part (lower Mintang Fm.).
In eastern Yunnan, the Panxi section is also represented by platform and platform marginal deposits. The benthic fossils (corals and brachiopods) have been studied by many workers (e.g. Hou and Xian 1964; Liao et al. 2006). Ambocoelioid brachiopods have been found in the probably upper Eifelian Nanpanjiang Fm. (Rhynchospirifer), in the Middle Givetian Qujing Fm. (Ambothyris and Emanuella), and in the Lower Frasnian Middle Member of the Yidade Fm. (Ambocoelia and Ladjia). The Lower Member of the Yidade Fm. has been demonstrated to be of the Upper Givetian by the occurrences of the brachiopod Stringocephalus nevadensis (Fig. 5(j1–j3)) and the conodont Po. cristatus, which is an Upper Givetian conodont (own data).
With the comprehensive study of Hou et al. (1988), the complete Devonian sequence of the Longmenshan area has been established (see Ma et al. 2009a for the column of litho- and biostratigraphy). Ambocoelioid brachiopods have been found in the lower Eifelian Shiliangzi Mbr of the upper Yangmaba Fm. (Amboglossa and Aviformia), in the upper Eifelian lower Jinbaoshi Fm. (Amboglossa and Ambothyris), in the Lower and Middle Givetian upper Jinbaoshi Fm. and the Guanwushan Fm. (Emanuella and Ambothyris) in the Upper Givetian upper Haijiaoshi Mbr of the Guanwushan Fm. (Emanuella and Ambothyris), and in the Lower and Middle Frasnian Tuqiaozi Fm. (Zhonghuacoelia). No specific age was provided for Diazoma wenchuanensis from the Givetian Guanwushan Fm. of Wenchuan (Xu et al. 1978).
According to Zhang et al. (1983) and Cao et al. (in XIGMR and NIGP 1987), ambocoelioid brachiopods in the Western Qinling include Amboglossa in the upper Emsian through upper Eifelian Dangduo to basal Xiawuna formations, Ambocoelia in the upper Eifelian part of the Lure Fm. and the Frasnian Lengshuihe Fm., Rhynchospirifer in the Lower Givetian part of the Xiawuna Fm., “Emanuella” (our quotation marks) in the Lower Frasnian upper Pulai Fm. (our note: true Emanuella is Givetian in South China; there is no description and illustrations for Emanuella sp. from the Pulai Fm., and thus, it is excluded from our discussion), and Crurithyris? (our question mark, Cr. minuta Zhang, 1983) in the Upper Frasnian lower part of the Cakuohe Fm. Ambothyris? (our quotation marks, including Emanuella curvimarginalis in Zhang et al. 1983) from the Dangduo Fm. without an exact stratigraphic position (upper Emsian to lower Eifelian). The Cakuohe Fm. yields Zhonghuacoelia, but the exact horizon is uncertain (Upper Frasnian to probably lower Famennian).
In addition, the uppermost Famennian part of the Nanbiancun Fm. in the Nanbiancun section of Guangxi yields Ambocoelia and Crurithyris (Yu 1988). The upper Emsian–lower Eifelian Tangxiang Fm. in the Nandan section of Guangxi bears Amboglossa.
Revised classification of the Ambocoeliidae George, 1931
Major morphological characteristics
According to Johnson et al. (2006), the superfamily Ambocoelioidea George, 1931 consist of four families of commonly small shells that are characterised by lacking well-developed fold and sulcus, but possessing a commonly simple, knoblike cardinal process, broad and well-developed outer hinge plates, and a variably developed cruralium. The two subfamily divisions of the Ambocoeliidae are based on the nature of crural plates, microornament, and dental plates: the Ambocoeliinae is characterised by vestigial or lacking crural plates, commonly fine concentric growth lamellae, and lacking dental plates, whereas the Rhynchospiriferinae is characterised by well-developed crural plates, commonly fine capillae, and variably developed dental plates. In fact, the development of crural plates and dental plates as well as the cardinal process is quite variable in the whole superfamily Ambocoelioidea. For example, in the Rhynchospiriferinae, Crurispina possesses a small fixed (sessile) cardinal process, short and discrete crural plates and lacking dental plates, which is similar to Ambocoelia (see transverse section of Goldman and Mitchell 1990, figs. 10, 11, 13, 14) of the Ambocoeliinae, whereas Crurithyris of the Ambocoeliinae completely lacks crural plates, with the dorsal hinge structure identical to that of many other spiriferides such as the superfamilies Martinioidea Waagen, 1883 and Reticularioidea Waagen, 1883 (see Lü and Ma 2017, fig. 16, Sun and Baliński 2011, fig. 23, for comparison of the two types: ambocoelioid type and non-ambocoelioid type dorsal hinge structure).
Many workers have questioned the use of dental plates as an important feature to divide the Ambocoeliidae (Nalivkin 1941, p. 217; Veevers 1959a, p. 124; Johnson and Trojan 1982). Our study shows that the development of dental plates is quite variable, from lack of dental plates (the so-called dental ridges) to well-developed dental plates. The micro-ornamentation is also variable, either in different species or in the same species, even in the same specimen at different shell areas and therefore cannot be solely used to divide the Ambocoeliidae. In addition, microornament may be seen at two different shell layers (see Xian 1983): surficial microornament on the primary layer (spines and pustules) and inner microornament after abrasion of the shell primary layer (capillae or pits), which is evidenced in Ladjia jiwozhaiensis (Fig. 5(a3, b3, c2)) and Ambothyris sp. (Fig. 11(d6)) of Guizhou and Emanuella sp. of Xiangzhou (Fig. 5(f6, f7)). Furthermore, the same species may display different types of microornament with different degrees of erosion (Baliński 1975), which is also evidenced in Ladjia jiwozhaiensis (Fig. 5(a3, b3, c2)). Therefore, the state of shell preservation is important for correct identification of the microornamentation.
To summarise, the classification scheme of the Ambocoeliidae based on the abovementioned features (Johnson et al. 2006) has various problems and inconsistencies. Some taxa that are included in the same subfamily on the basis of similar short crural plates may be quite different in the other internal structures. For example, in the subfamily Ambocoeliinae, Ambocoelia has a pair of small crural plates and a bilobed cardinal process, whereas Guangxiispirifer has inner hinge plates united into a triangular platform and a prominent (single nodular) cardinal process. In addition, crural plates may be shown to be short or vestigial for shells with a low dorsal area and convex ventral umbo, in which crural plates are completely or mostly buried in the secondary shell thickening. This type of “lacking crural plates” is fundamentally different from “the lack of crural plates” in Crurithyris (non-ambocoelioid type dorsal hinge structure), which implies that Crurithyris may not be an ambocoelioid. Therefore, to achieve a uniform and consistent classification scheme, more characteristics need to be evaluated, e.g. nature of the cardinal process and cruralium.
Bilobed type (Fig. 6a): the cardinal process is cemented on the shell bottom, being bilobed or bi-knobbed in shape (in ventral view), e.g. Ambocoelia and Metaplasia.
Triangular-knobbed type (Fig. 6b): it is also directly cemented on the shell bottom, but triangle-shaped in ventral view, e.g. Ladjia.
Single-knobbed type (Fig. 6d): a single-knobbed cardinal process is supported by a single plate from bottom (median septum), with or without a coronal-like structure (muscle attachment) on top of the cardinal process.
The cardinalia with the Bilobed type, Triangular-knobbed type, and Ctenophoridium-like type cardinal process is characterised by the sessile crural plates (i.e. attached to the shell bottom; Fig. 6a–c).
Broad-sessile type (Fig. 7a): the cruralium is low and broad, sitting on the shell bottom (Fig. 7a). The socket plates diverge laterally at an angle equal to or greater than 90°. The crural plates are short and rudimentary; the crural bases are subrounded in cross section. This type of cruralium is usually characteristic of the taxa with the Bilobed type cardinal process, e.g. Ambocoelia (here referred as the Ambocoelia-type cardinalia).
Narrow-sessile type (Fig. 7b): the cruralium is low and narrow, sitting on the shell bottom (Fig. 7b). The socket plates are from nearly parallel vertically to divergent laterally at an angle smaller than 90°, resulting in a narrow and deep cruralium and notothyrial cavity. The crural plates are relatively developed, discrete, or united with each other; the crural bases are also subrounded in cross section. Taxa with this type of cruralium are usually characterised by Triangular-knobbed type cardinal process or Ctenophoridium-like type cardinal process. The combination of the Narrow-sessile type cruralium and the Ctenophoridium-like type cardinal process is here referred as the Emanuella-type cardinalia.
Elevated type (Fig. 7c): distinct from the two previous types, this type of cruralium is characterised by poorly developed socket plates with blade-like crural bases on their inner sides and well-developed crural plates that are united to form a V- or U-shaped cruralium, supported or unsupported by a median septum. Taxa with this type of cruralium are usually characterised by single-knobbed type cardinal process, e.g. Rhynchospirifer (here referred as the Rhynchospirifer-type cardinalia).
In the classification of Johnson et al. (2006), taxa of the Rhynchospirifer-type cardinalia are placed in both subfamilies, e.g. Guangxiispirifer of the Ambocoeliinae and Rhynchospirifer of the Rhynchospiriferinae, whereas taxa with different types of cardinalia were placed in the same subfamily, e.g. Guangxiispirifer and Ambocoelia in the Ambocoeliinae and Rhynchospirifer and Emanuella in the Rhynchospiriferinae. Our study supports the notion of Xian (1983) who elevated Rhynchospiriferinae Paulus, 1957 to the family level since their Rhynchospirifer-type cardinalia is a distinct character that distinguishes them from the rest of the Ambocoeliidae, which is, as represented by Ambocoelia, Emanuella, and Diazoma (previously in the Ambocoeliinae and the Rhynchospiriferinae, respectively), characterised by the sessile crural plates.
Superfamily Ambocoelioidea George, 1931
Family Ambocoeliidae George, 1931
Crural plates variably present, vestigial or well developed, discrete or connected with each other on the valve floor; cruralium of the Broad- and Narrow-sessile types; cardinal process varied, Bilobed, Triangular-knobbed, and Ctenophoridium-like types; crural bases commonly rounded; dental plates commonly lacking, except for a few genera in which they are weakly developed.
Genera included (those present in the Devonian of South China):Ambocoelia Hall, 1860, Ambothyris* George, 1931, Aviformia Xian, 1988, Choperella* Liashenko, 1969, Crurispina* Goldman and Mitchell, 1990, Cyrtinoides Yudina and Rzhonsnitskaia, 1985, Diazoma* Dürkoop, 1970, Emanuella* Grabau, 1923, Ilmenia* Nalivkin, 1941, Ilmospirifer* Liashenko, 1969, Ladjia* Veevers, 1959, Moravilla* Havlíček, 1953, and Zhonghuacoelia* Chen, 1978 (genera with an asterisk were previously in the Rhynchospiriferinae of Johnson et al. (2006); Crurithyris George, 1931 is probably not a ambocoelioid because of its non-ambocoelioid type dorsal hinge structure).
Family Rhynchospiriferidae Paulus, 1957
[nom. transl. Xian in Xian and Jiang 1978, ex Rhynchospiriferinae Paulus, 1957]
Crural plates developed, commonly joined to form an Elevated type cruralium supported by median septum or suspended from valve floor anteriorly; cardinal process of the Single-knobbed type; crural bases commonly elongated and blade-like in transverse section; dental plates commonly well developed (except in Guangxiispirifer and Amboglossa: weak or vestigial).
Genera included (those present in the Devonian of South China):Rhynchospirifer Paulus, 1957, Amboglossa Wang and Zhu, 1979, Changtangella Xian, 1983, Levibiseptum Xian in Hou and Xian, 1975, Ilmeniopsis Xian, 1983, Ilmenispina Havlíček, 1959, Kosirium Ficner and Havlíček, 1975, and Guangxiispirifer* Xian, 1983 (genus with an asterisk was previously in the Ambocoeliinae of Johnson et al. 2006).
Origination and diversification of the ambocoelioids in South China
Immigration, endemism, and originations
North America is apparently the centre of origin for the Ambocoelioidea (Fig. 3). We agree that the tiny, small, smooth Ambocoelioidea evolved directly from the cyrtioids in the middle Silurian by the paedomorphic loss of ribbing (Carter and Gourvennec 2006) and that specifically the Eospiriferinae may be the ancestor (Pitrat 1965, p. H667; Johnson and Lenz 1992). According to Johnson and Lenz (1992), Gourvennec (2000), and Johnson et al. (2006), the oldest ambocoelioid genus is Eoplicoplasia in the late Wenlock of the Silurian, which is assigned to the Ambocoeliinae on the basis of its lacking crural plates. However, the so-called lack of crural plates needs further clarification because no serial sections were presented. For example, Goldman and Mitchell (1990) demonstrated through serial sections that Ambocoelia has short crural plates, which had commonly been known or described to lack crural plates. Dicoelospirifer (late Wenlock of Canadian Arctic Islands) serves as another alternative ancestor of the smooth-shelled ambocoeliids (Zhang 1989b) since its type species possesses short crural plates (Zhang 1991), although the author gave the statement “lacks crural plates” in the genus diagnosis. Zhang (1991) mentioned that, “It shows that from the very beginning the Ambocoeliinae were divided into non-plicate and plicate forms. It is possible that Dicoelospirifer is an ancestor of non-plicate ambocoeliids while Plicoplasia (=Eoplicoplasia; our note: Plicoplasia cf. acutiplicata of Zhang 1989b is reassigned to Eoplicoplasia) is an ancestor of plicate ones.” Compared with the non-plicate Dicoelospirifer, plicate Eoplicoplasia is more likely to be the ancestor of the smooth ambocoelioids for the following reasons. Plications decreased in strength in early intermediate forms of the ambocoelioids, e.g. Metaplasia hemicona (Fig. 3a, Havlíček 1990, from Czechia), which is considered to be (upper) Ludlow (Manda and Kříž 2006; Manda and Frýda 2014; Kraft and Kvaček 2017) to earliest Pridoli in age, Pridoli Metaplasia sp. (Lenz 1970, from Yukon), Lochkovian Ambothyris? inopis (Fig. 3: b, Mawson and Talent 1999, from southeastern Australia; our note: it should probably be assigned to Ambocoelia or Metaplasia), Metaplasia cf. lenzi (Fig. 3c, Lenz and Johnson 1985, from southeastern Australia) and Ambocoelia bubovica (Fig. 3d, Mergl 2003, from Bohemia), Pragian Ambocoelia aff. praecox (Fig. 3f, Lenz 1977, from Yukon). Dicoelospirifer differs from other early ambocoelioids in its bilobed-emarginated outline and poorly developed ventral interarea. The third earliest smooth-shelled ambocoeliid is Metaplasia, which represented an intermediate stage from the plicate to smooth forms. In the Silurian species Me. hemicona, the plications are still present, but much weaker than those of Eoplicoplasia (Fig. 2(b)); therefore, Metaplasia of the Ludlow is probably an intermediate genus linking to the Devonian forms.
During the Devonian, there were not only diverse cosmopolitan genera such as Cyrtinoides (Fig. 3: genus no. 6), Emanuella (Fig. 3: genus no. 17), Ambothyris (Fig. 3: genus no. 13), and Ladjia (Fig. 3: genus no. 22), but also numerous endemic genera (Fig. 3: genus nos. 27–29). It should be pointed out that those cosmopolitan genera are generally ambocoeliids whereas the rhynchospiriferids are basically restricted and short lived and have not been found in Laurentian (North America) and Gondwana, including Rhynchospirifer (Fig. 3: genus no. 11), Kosirium (Fig. 3: genus no. 21), Amboglossa (Fig. 3: genus no. 12), and Guangxiispirifer (Fig. 3: genus no. 30). In the latest Eifelian and Early Givetian, the Rhynchospiriferidae became diversified with quite a few endemic genera (Changtangella, Ilmeniopsis, and Levibiseptum) and lasted shortly before its final disappearance in South China at the end of the Early Givetian (Fig. 8).
The few endemic ambocoeliid genera include Zhonghuacoelia and Aviformia (poorly preserved). Zhonghuacoelia probably originated from Ambocoelia in light of its Ambocoelia-type cardinalia, whereas those cosmopolitan ambocoeliid genera are immigrants at various marine transgression episodes. The only genus that crosses the Frasnian–Famennian boundary in South China seems to be Ambocoelia. True Crurithyris probably first appeared in South China in the latest Famennian with a different cardinalia structure, which, along with other post-Devonian forms such as Attenuatella, Biconvexiella, and Cruricella, may represent a different evolutionary lineage.
Ladjia and Emanuella are very similar externally; their major difference lies in that the former is characterised by the Triangular-knobbed cardinal process, which implies that Ladjia should be a direct descendant of Emanuella. Emanuella and Diazoma are characterised by the Ctenophoridium-like type cardinal process and may be derived from Ambothyris. The Emanuella-type cardinalia having a more complicated cardinal process seems more advanced than the Ambocoelia-type cardinalia, which suggests that taxa of the former type are derived from the Ambocoelia-type taxa. The earliest genus of the Emanuella-type taxa is Ambothyris (Chatterton 1973, from the Receptaculites and Warroo limestones at Taemas, Fig. 3g) in the early Emsian of Australia (Lindley 2002, p. 111). Therefore, the differentiation of the Emanuella-type from the Ambocoelia-type should take place no later than (during or before) the early Emsian. Morphologically, all rhynchospiriferids are characterised by the Rhynchospirifer-type cardinalia. As the earliest genus of the Rhynchospiriferidae, Amboglossa possesses a median furrow on both valves, which also can be observed in Ambothyris, implying the high possibility that Rhynchospirifer-type forms are derived from the Emanuella-type forms. Such characteristics were also present in the lower Eifelian Guangxiispirifer bisinuatus but disappeared in the Lower Givetian Guangxiispirifer (Xian 1983). Therefore, Guangxiispirifer should be derived from Amboglossa. Other non-furrow rhynchospiriferid genera suddenly emerged at the basal Mintang Fm., which should originate from Rhynchospirifer. Prolazutkinia and Lazutkinia together constitute an evolutionary lineage because of their strong plication. Rhynchospiriferids and lazutkiniids are both characterised by the Rhynchospirifer-type cardinalia; therefore, they are closely related and possibly derived from the Ambocoeliidae.
To sum up, the origin of the Ambocoelioidea took place in northern North America during the Wenlock. Within the superfamily, various taxa may have their own place and time of origin. When early immigrants entered a new habitat, they may rapidly evolve into new forms. These new taxa may further expand their distribution into other continents. The Rhynchospiriferidae is such an example, which originated in South China and migrated into the Baltica continent. In light of the cardinalia evolution, the Ambocoelia-type taxa are ancestral forms for all the Ambocoelioidea. The differentiation of the Emanuella-type from the Ambocoelia-type should take place no later than (during or before) the early Emsian. The origination of the Rhynchospirifer-type taxa took place in South China and their differentiation from the Emanuella-type taxa probably happened in the upper Emsian.
Diversification and sea level changes
In South China, the first ambocoelioids Amboglossa and Prolazutkinia occurred in the upper part of the Dale Formation (upper Emsian), which consists of deposits indicative of a sea level rise environment (Dale sea level rise of Ma et al. 2017). The first Ambothyris appeared in the lower Dangduo Fm. of the Tewa area (Fig. 8), which is mainly composed of biogenic limestone and was probably also related to the Dale sea level rise (Fig. 8; Ma et al. 2017). The primary differentiation of the rhynchospiriferids is the appearances of Guangxiispirifer and Rhynchospirifer in the early Eifelian, probably related to the Gupa transgression (Chotec Event) at the end of the Po. partitus Zone (Ma et al. 2017). These two rhynchospiriferid genera are important for the subsequent radiation of the Rhynchospiriferidae in South China towards the end of the Eifelian, which was probably related to the Mintang transgression (Kacak Event) in the Po. ensensis Zone (Ma et al. 2017). After this radiation, the Rhynchospiriferidae reaches its highest diversity at the end of the Eifelian through Lower Givetian (six to seven genera) and apparently died out immediately afterwards in the main part of South China. This regional extinction happened within the Po. hemiansatus Zone (conodont data of Bai et al. 1994 in the Liujing section), which might be related to the Songjiaqiao sea level fall (Fig. 8). In the Qinling region (e.g. the Tewo area), rare rhynchospiriferids may range slightly higher, but still within Lower Givetian. In contrast, the Ambocoeliidae, which has more cosmopolitan genera, had no radiation event; its diversity increased gradually and reached the highest diversity (six genera) in the Middle–Upper Givetian. Ambocoeliid diversity started to decline in the Early Frasnian and continued towards the end of the Famennian.
Ambocoelioids are a group of strongly facies-controlled brachiopods. Their emergence and demise show a close relationship with sea level changes. The ambocoeliids are generally preserved in marl and shale intervals suggestive of deeper dysoxic environments, whereas rhynchospiriferids-bearing strata are often associated with reefal limestones, representing a high-energy and well-oxygenated environment (Xian 1983). Their different adaptions probably resulted in their different responses to environmental changes. The rhynchospiriferids were probably more sensitive to sea level changes, therefore prone to rapid and regional originations and extinctions. The ambocoeliids, inhabiting deeper water environments and having more cosmopolitan genera, underwent gradual originations, extinctions, and diversity changes.
All specimens with the prefix PUM are stored in the Geological Museum of Peking University.
Family Ambocoeliidae George, 1931
Genus Ambocoelia Hall, 1860
Ambocoelia yidadeensis sp. nov.
Derivation of name: Name after Yidade, a village, which is the type locality of the Panxi section.
Holotype: PUM16109 (Fig. 9(h)).
Diagnosis: Shell material thick in ventral umbo, ventral interarea relatively high, moderately curved; fold and sulcus lacking; spine bases broken off (giving a pitted appearance), which are densely arranged in a quincunx shape; faint striae widely spaced on exfoliated dorsal shell.
Description: Small-sized, generally around 10 mm in width; ventral valve more convex than dorsal valve, especially in the umbonal area; ventral umbo weakly inflated, beak strongly incurved; ventral interarea high; apical plate closing delthyrium apex, remains of deltidial plates along delthyrial edges; dorsal interarea very low; fold and sulcus lacking, some specimens displaying a shallow median depression near anterior margin on both valves; commissure rectimarginate; faint concentric growth lamellae; pits (after spine bases broken off) on primary layer, uniform in size, densely arranged in a quincunx shape; widely spaced faint radial striae on exfoliated dorsal valve.
Internally only dental ridges developed; teeth strong, triangular; cardinal process of the Bilobed type; hinge sockets deep, outer socket ridges partly fused to valve floor posteriorly; crural bases rounded, crural plates short; cruralium of the Broad-sessile type; crura small, rounded; spiralia about six–seven whorls.
Discussion: the new species differs from the type species Ac. umbonata in the higher and flatter ventral interarea, more convex dorsal valve and more indistinct median furrow. Ac. elongata Zhang, 1983 from the upper Eifelian Lure Fm. is smaller in size and has an elongated outline. Ac. pseudosinensis Zhang, 1983 from the Frasnian Lengshuihe Fm. shares some similarities externally, but differs from our specimen in having a shorter hinge line, more convex dorsal valve and more elevated socket plates.
Occurrence: Middle Yidade Formation of the Panxi section (stratigraphic column see Zhang et al. 2015, Panxi-Y2, Bed 9), Lower Frasnian.
Genus Ambothyris George, 1931
Ambothyris panxiensis (Chu, 1974)
1974 Ambocoelia panxiensis Chu; Fang and Zhu, p. 414, pl. 135, fig. 8–9.
1974 Ambothyris yunnanensis Wang et al. p. 244, pl. 124, fig. 6–9.
1982 Emanuella aff. transversa, Bai et al. p. 12–13.
Description: Small-sized, generally around 5–10 mm in width, transverse in outline; dorsal valve arch-shaped; sub-equally biconvex; ventral beak small, strongly incurved; ventral interarea high; dorsal interarea low; fold and sulcus lacking, except for a faint median furrow on both valves; commissure rectimarginate or slightly sulcate; faint concentric growth lamellae.
Internally dental plates lacking, dental ridges strongly developed; very small apical plate closing the delthyrium apex; cardinal process of the Ctenophoridium-like type, apical vacuity developed; hinge socket plates high, crural plates short, cruralium of the Narrow-sessile type, crural bases rounded; spiralia at least six whorls.
Discussion: This species differs from other species such as At. yunnanensis (Chu in Fang and Zhu 1974), At. parvissima (Yang, 1988) and At. sp. (Fig. 11(d)) in its transverse outline and the arch-shaped dorsal valve. At. longmenshanensis has a very high ventral interarea, which is easily distinguishable from At. panxiensis. Our examination of specimens of Emanuella aff. transversa listed in Bai et al. (1982, pp. 12–13) and Bai et al. (1994, p. 141) shows that they clearly differ from Emanuella in the higher and flatter ventral interarea and that they should be assigned to Ambothyris panxiensis.
Ambothyris panxiensis (Chu, 1974) and Ambothyris yunnanensis Wang et al., 1974 are synonyms because both of them are from the Qujing Fm. of the Panxi section and are very similar morphologically. The two publications appeared in the same time (all November of 1974). As the first revisers, we choose Ambothyris panxiensis (Chu, 1974) as the valid species name. This can avoid to change the name Ambocoelia yunnanensis Chu in Fang and Zhu 1974 (which is a valid species and should also be assigned to Ambothyris). Ambothyris yunnanensis (Fig. 11(e)) can be distinguished from At. panxiensis (Fig. 11(a–c)) by its subpentagonal outline in adult individuals.
Occurrence: Yingtang Formation, Baqi section, Xiangzhou, Eifelian.
Family Rhynchospiriferidae Paulus, 1957
Genus Rhynchospirifer Paulus, 1957
Material: One specimen.
Diagnosis: Inflated; cardinal extremities rounded; ventral interarea moderately high and strongly incurved; microornament of concentric rows of dense spiny bases on primary layer.
Description: Small- to medium-sized, ventribiconvex, inflated; cardinal extremities rounded; maximum width near the posterior margin; ventral interarea moderately high and strongly incurved; fold and sulcus lacking; front commissure rectimarginate; faint concentric growth lamellae; microornament of concentric rows of dense spiny bases on primary layer.
Internally dental plates convergent ventrally; cardinal process of the Single-knobbed type (ridge-shaped anteriorly); outer socket ridges fused to valve floor posteriorly; socket plates short, crural bases blade-shaped, crural plates forming an Elevated type cruralium, which is V-shaped, supported by a median septum; muscle scars deep.
Discussion: The species has a rounded cardinal extremity and strongly incurved ventral interarea; thus, it differs from other Chinese species such as Rh. liujingensis, Rh. trigonus, and Rh. hengxianensis and may represent a new species. Rh. regularis is the most similar species, but differs from the species in the sub-rectangular outline and having a wide flat depression near the anterior margin on both valves.
The species differs from the type species Rh. halleri in having an inflated shell a wider hinge (thus, maximum width is near the posterior margin) and a V-shaped cruralium (U-shaped in the type species).
Occurrence: Nanpanjiang Fm. (probably upper Eifelian) of the Panxi section
The origination of the Ambocoelioidea took place in northern North America during the Wenlock. The earliest form is the plicated ambocoeliid Eoplicoplasia from Canadian Arctic Islands. The second earliest largely smooth shelled ambocoeliid Metaplasia of the Ludlow is probably an intermediate genus linking to the Devonian forms.
Our study shows that the cardinal process and cruralium are quite varied and complicated. At least four types of the cardinal process (Bilobed, Triangular-knobbed, Ctenophoridium-like, and Single-knobbed type) and three types of cruralium (Broad-sessile, Narrow-sessile, and Elevated types) are recognised in the Ambocoelioidea. Based on differences in the cardinal process and cruralium, three types of cardinalia, Ambocoelia-type, Emanuella-type, and Rhyncospirifer-type, can be distinguished. It is justified to elevate the Rhynchospiriferinae Paulus, 1957 to the family level since their Rhynchospirifer-type cardinalia (with the Single-knobbed cardinal process and the Elevated type cruralium) is a distinct character that distinguishes them from the rest of the Ambocoeliidae George, 1931.
The temporal and spatial distributions of the superfamily Ambocoelioidea are depicted globally and in South China. Three earliest ambocoelioids in South China are Ambothyris, Amboglossa, and Prolazutkinia in the upper Emsian; the latter two genera originated in South China, and Amboglossa is probably the ancestor of the whole Rhynchospiriferidae family. In light of the cardinalia evolution, Ambocoelia-type is the first of all ambocoelioids. The differentiation of the Emanuella-type from the Ambocoelia-type cardinalia should take place in the early Emsian or before. The Rhynchospiriferidae (characterised by the Rhynchospirifer-type cardinalia) originated in South China in the late Emsian. The Rhynchospiriferidae and the Lazutkiniidae are both characterised by the Rhynchospirifer-type cardinalia and therefore are closely related, but they were possibly independently derived from the Ambocoeliidae.
The Ambocoelioidea is a group of strongly facies-controlled brachiopods. Their emergence and demise show a close relationship with sea level changes. The first appearance of the ambocoelioids in South China was in the late Emsian, which was probably related to the Dale sea level rise (=Upper Zlichov Event). The radiation of the endemic rhynchospiriferids in the basal Mintang Fm. was apparently related to the Mintang transgression (=Kacak Event). Because of different environmental adaptations, ambocoeliids and rhynchospiriferids show different modes of diversity variation and extinction. The ambocoeliids inhabited deeper and dysoxic water environments and showed greater capabilities to migrate and survive extinctions, and therefore, they are largely cosmopolitan in distribution. By contrast, rhynchospiriferids prefer a high-energy and well-oxygenated water environment; thus, they are probably more sensitive to sea level changes, and as a result, they are mostly endemic in distribution, being prone to rapid and regional extinctions.
A number of colleagues and students are thanked for their help in the fieldwork and during the preparation of this paper, including Zhang Yubo (Peking University), Zong Pu (Chinese Academy of Geological Sciences), and Lü Dan (Research Institute of Petroleum Exploration and Development). Andrzej Baliński (Instytut Paleobiologii PAN) was thanked for providing some reference papers. This manuscript benefited from comments by Andrzej Baliński and an anonymous reviewer.
This work was supported by the National Natural Science Foundation of China (Grant 41290260).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Bai, S. L., Jin, S. Y., & Ning, Z. S. (1982). Devonian biostratigraphy in Guangxi and related areas. Beijing: Peking University Press [in Chinese].Google Scholar
- Bai, S. L., Bai, Z. Q., Ma, X. P., Wang, D. R., & Sun, Y. L. (1994). Devonian events and biostratigraphy of South China. Beijing: Peking University Press.Google Scholar
- Baliński, A. (1975). Secondary changes in micro–ornamentation of some Devonian ambocoeliid brachiopods. Palaeontology, 18(1), 179–189.Google Scholar
- Baliński, A., Racki, G., & Halamski, A. T. (2016). Brachiopods and stratigraphy of the Upper Devonian (Frasnian) succession of the Radlin Syncline (Holy Cross Mountains, Poland). Acta Geophysica Polonica, 66(2), 107–156.Google Scholar
- Becker, R. T. (2007). Message from the chairman. Subcommission on Devonian. Stratigraphy Newsletter, 22, 1–2.Google Scholar
- Beus, S. S. (1965). Devonian faunule from the Jefferson Formation, central Blue Spring Hills, Utah–Idaho. Journal of Paleontology, 39(1), 21–30.Google Scholar
- Boucot, A. J. (1959). Early Devonian Ambocoeliinae (Brachiopoda). Journal of Paleontology, 53, 16–24.Google Scholar
- Boucot, A. J., & Lawson, J. D. (1999). Paleocommunities—a case study from the Silurian and Lower Devonian. New York: Cambridge University Press.Google Scholar
- Boucot, A. J., Gauri, K. L., & Southard, J. (1970). Silurian and Lower Devonian brachiopods, structure and stratigraphy of the Green Pond Outlier in southeastern New York. Palaeontographica Abteilung A, 135(1–2), 1–59.Google Scholar
- Brice, D., Lafuste, J., Lapparent, A. F. D., Pillet, J., & Yassini, I. (1973). Étude de deux gisements paléozoiques (Silurien et Dévonien) de l‘Elbourz oriental (Iran). Annales Societe Geologique du Nord, 93, 171–218.Google Scholar
- Caldwell, W. G. E. (1967). Ambocoeliid brachiopods from the Middle Devonian rocks of northern Canada. In D. H. Oswald (Ed.), International symposium on the Devonian system (pp. 601–616). Alberta: Alberta Society of Petroleum Geologists Calgary.Google Scholar
- Carter, J. L., & Gourvennec, R. (2006). Introduction. In R. L. Kaesler (Ed.), Treatise on invertebrate paleontology, part H: Brachiopoda revised, volume 5 (pp. 1689–1694). Lawrence: The Geological Society of America and the University of Kansas Press.Google Scholar
- Chatterton, B. D. E. (1973). Brachiopods of the Murrumbidgee Group, Taemas, New South Wales. Bulletin, Bureau of Mineral Resources, Geology and Geophysics of Australia, 137, 1–146.Google Scholar
- Chatterton, B. D. E., & Perry, D. G. (1978). An early Eifelian invertebrate faunule, Whittaker Anticline, northwestern Canada. Journal of Paleontology, 52(1), 28–39.Google Scholar
- Chen, Y. R. (1984). Brachiopods from the Upper Devonian Tuqiaozi Member of the Longmenshan area (Sichuan, China). Palaeontographica Abteilung, A, 184(5–6), 95–166.Google Scholar
- Cherkesova, S. V. (1988). Lower and Middle Devonian marine deposits of the Soviet arctic and the correlation with arctic Canada. In N. J. McMillan, A. F. Embry, & D. J. Glass (Eds.), Devonian of the world, volume III (pp. 669–679). Calgary: Canadian Society of Petroleum Geologists.Google Scholar
- Chlupáč, I. (1982). The Bohemian Lower Devonian stages. Courier Forschungsinstitut Senckenberg, 55, 345–400.Google Scholar
- Chlupáč, I., Havlíček, V., Kriz, J., Kukal, Z., & Storch, P. (1998). Palaeozoic of the Barrandian (Cambrian to Devonian). Czech Geological Survey, 1–183.Google Scholar
- Cooper, G. A., & Dutro, J. T. (1982). Devonian brachiopods of New Mexico. Bulletins of American Paleontology, 82–83(315), 1–215.Google Scholar
- Day, J. (1988). The brachiopod succession of the Late Givetian–Frasnian of Iowa. In N. J. McMillan, A. F. Embry, & D. J. Glass (Eds.), Devonian of the world, volume III (pp. 303–325). Calgary: Canadian Society of Petroleum Geologists.Google Scholar
- Day, J. (1996). Faunal signatures of Middle–Upper Devonian depositional sequences and sea level fluctuations in the Iowa Basin: US midcontinent. Geological Society of America Special Paper, 306, 277–300.Google Scholar
- De Keyser, T. L. (1977). Late Devonian (Frasnian) brachiopod community patterns in western Canada and Iowa. Journal of Paleontology, 51(1), 181–196.Google Scholar
- Dürkoop, A. A. (1970). Braehiopodeo aus dem Silur, Devon und Karbon in Afghanistan (mit einer Stratigraphie des Palaozoikum der Dascht–E–Nawar/Ost und yon Rukh). Palaeontographica Abteilung A, 134(4–6), 153–225.Google Scholar
- Fagerstrom, J. A. (1961). The fauna of the Middle Devonian Formosa Reef Limestone of southwestern Ontario. Journal of Paleontology, 35(1), 1–48.Google Scholar
- Fang, R. S., & Zhu, X. S. (1974). Brachiopoda. In Geological Bureau of Yunnan Province (Ed.), Fossil atlas of Yunnan Vol. 1 and 2 (pp. 285–480). Kunming: Yunnan People’s Publishing House.Google Scholar
- Farrell, J. R. (1992). The Garra Formation (Early Devonian: Late Lochkovian) between Cumnock and Larras Lee, New South Wales, Australia: stratigraphic and structural setting, faunas, and community sequence. Palaeontographica Abteilung A, 222(1–3), 1–41.Google Scholar
- Ficner, F., & Havlíček, V. (1978). Middle Devonian brachiopods from Celechovice, Moravia. Sbornik geologickych ved, Paleontologie, 21, 49–106.Google Scholar
- Frost, S. H., & Langenheim, R. L. (1966). Paleontology of the Stringocephalus Biostrome, Piute Formation (Middle Devonian), Arrow Canyon Range, Clark County, Nevada. Journal of Paleontology, 40, 911–930.Google Scholar
- GBDMR (Gansu Bureau of Geology and Mineral Resources). (1989). Regional geology survey in Gansu province. Beijing: Geological Publishing House [in Chinese].Google Scholar
- Gourvennec, R. (2000). The evolution, radiation and biogeography of early spiriferid brachiopods. Records of the Western Australian Museum Supplement, 58, 335–347.Google Scholar
- Gourvennec, R., & Carter, J. L. (2007). Spiriferida and Spiriferinida. In P. A. Selden (Ed.), Treatise on invertebrate paleontology, part H: Brachiopoda revised, volume 6 (pp. 2772–2796). Lawrence: The Geological Society of America and the University of Kansas Press.Google Scholar
- Grabau, A. W. (1931). Devonian Brachiopoda of China, I: Devonian Brachiopoda from Yunnan and other districts in South China. Palaeontologia Sinica, Series B, 3(3), 1–545. Plates publised in 1933.Google Scholar
- Havlíček, V. (1953). O nekolika novych ramenonozcich Ceskeho a Moravskeho Stredniho Devonu. Ustredního Ustav Geologicky, Vestnik, 28, 4–9 1 pl.Google Scholar
- Havlíček, V. (1959). Spiriferidae v Ceském Siluru a Devonu (Brachiopoda) [The Spiriferidae of the Silurian and Devonian of Bohemia]. Ustredního Ustavu Geologického, Rozpravy, 25, 1–275 28 pl.Google Scholar
- Havlíček, V. (1990). Systematic palaeontology: class Articulata. In V. Havlíček & P. Štroch (Eds.), Silurian brachiopods and benthic communities in the Prague Basin (Czechoslovakia) (pp. 45–243). Rozpravy, 48: Ustredního Ustavu Geologického.Google Scholar
- Havlíček, V. (1998). Review of brachiopods in the Chapel Coral Horizon (Zlíchov Formation, lower Emsian, Lower Devonian, Prague Basin). Věstník Českého geologického ústavu, 73(2), 113–132.Google Scholar
- Havlíček, V., & Kukal, Z. (1990). Sedimentology, benthic communities, and brachiopods in the Suchomasty (Dalejan) and Acanthopyge (Eifelian) Limestones of the Koneprusy area (Czechoslovakia). Sbornik geologickych ved, Paleontologie, 31, 105–205.Google Scholar
- Herrera, Z. A. (1995). The Lower Devonian chonetoidean brachiopods from the Argentine Precordillera. Documents des Laboratoires de Geologie Lyon, 136, 101–147.Google Scholar
- Hou, H. F. (1978). Devonian strata in South China. In Institute of Geology, Mineral Resources, Chinese Academy of Geological Sciences (Ed.), Symposium on the Devonian strata of South China (pp. 214–230). Beijing: Geological Publishing House [in Chinese].Google Scholar
- Hou, H. F., & Wang, S. T. (1988). Stratigraphy of China Vol.7 The Devonian System on China. Beijing: Geological Publishing House [in Chinese].Google Scholar
- Hou, H. F., & Xian, S. Y. (1964). Brachiopod fauna of the Nanpanjiang limestone of eastern Yunnan and its geological age. Acta Palaeontologica Sinica, 12(3), 411–425.Google Scholar
- Hou, H. F., & Xian, S. Y. (1975). Lower to Middle Devonian brachiopods from Guangxi and Guizhou. Professional Papers of Stratigraphy and Palaeontology Palaeontology, 1, 1–85 in Chinese with English abstract.Google Scholar
- Hou, H. F., Wan, Z. Q., Xian, S. Y., Fan, Y. N., Tang, D. Z., & Wang, S. T. (1988). Devonian stratigraphy, paleontology and sedimentary facies of Longmenshan. In Sichuan. Beijing: Geological Publishing House in Chinese with English abstract.Google Scholar
- Hou, H. F., Chen, X. Q., Rong, J. Y., Ma, X. P., Zhang, Y., Xu, H. K., Su, Y. Z., Xian, S. Y., & Zong, P. (2017). Devonian brachiopod genera on type species of China. In J. Y. Rong, Y. G. Jin, S. Z. Shen, & R. B. Zhan (Eds.), Phanerozoic brachiopod genera of China (pp. 343–557). Beijing: Science Press.Google Scholar
- Isaacson, P. E. (1977). Devonian stratigraphy and brachiopod paleontology of Bolivia. Part A: Orthida and Strophomenida. Palaeontographica Abteilung A, 155(5–6), 133–192.Google Scholar
- Jiang, D. Y., Ding, G., & Bai, S. L. (2000). Conodont biostratigraphy across the Givetian–Frasnian boundary (Devonian) of Liujing, Guangxi. Journal of Stratigraphy, 24, 195–200 [in Chinese with English abstract].Google Scholar
- Jin, X. C. (1988). Early Middle Devonian brachiopod biostratigraphy in Guangxi with a discussion on the Middle Devonian event. Professional Papers of Stratigraphy and Palaeontology, 21, 193–231 [in Chinese with English abstract].Google Scholar
- Johnson, J. G. (1970). Great basin Lower Devonian Brachiopoda. Geological Society of America Special Paper, 131, 1–421.Google Scholar
- Johnson, J. G. (1971). Lower Givetian brachiopods from Central Nevada. Journal of Paleontology, 45(2), 301–326.Google Scholar
- Johnson, J. G. (1974). Early Devonian brachiopod biofacies of Western and Arctic North America. Journal of Paleontology, 48(4), 809–819.Google Scholar
- Johnson, J. G., & Trojan, W. R. (1982). The Tecnocyrtina brachiopod fauna (? Upper Devonian) of central Nevada. Geologica et Palaeontologica, 16(1), 19–150.Google Scholar
- Johnson, J. G., Reso, A., & Stephens, M. (1969). Late Upper Devonian brachiopods from the West Range limestone of Nevada. Journal of Paleontology, 43(6), 1351–1368.Google Scholar
- Johnson, J. G., Carter, J. L., & Hou, H. F. (2006). Ambocoelioidea. In R. L. Kaesler (Ed.), Treatise on invertebrate paleontology, part H: Brachiopoda revised, volume 5 (pp. 1733–1746). Lawrence: The Geological Society of America and the University of Kansas Press.Google Scholar
- Kelus, A. (1939). Devonische Brachiopoden und Korallen der Umgebung von Pełcza in Volhynien. Biuletyn Pánstwowego instytutu geologicznego, 8, 1–51.Google Scholar
- Kesling, R. V., & Chilman, R. B. (1975). Strata and megafossils of the Middle Devonian Silica Formation. University of Michigan Papers on Paleontology, 8, 1–408.Google Scholar
- Klovan, J. E. (1964). Facies analysis of the Redwater Reef Complex, Alberta, Canada. Bulletin of Canadian Petroleum Geology, 12, 1–100.Google Scholar
- Kuang, G. D., Zhao, M. T., & Tao, Y. B. (1989). The standard Devonian section of China: Liujing section of Guangxi. Wuhan: China University of Geosciences Press [in Chinese with English abstract].Google Scholar
- Lenz, A. C. (1970). Late Silurian brachiopods of Prongs Creek, northern Yukon. Journal of Paleontology, 44, 480–500.Google Scholar
- Lenz, A. C. (1972). Plicocyrtina and Plicoplasia (Brachiopoda) from the Lower Devonian of the northern Cordillera. Journal of Paleontology, 46, 99–103 2 pl.Google Scholar
- Lenz, A. C. (1977). Upper Silurian and Lower Devonian brachiopods of Royal Creek, Yukon, Canada. Part 1, Orthoida, Strophomenida, Pentamerida, Rhynchonellida. Part 2, Spiriferida: Atrypacea, Dayiacea, Athyridacea, Spiriferacea. Palaeontographica Abteilung A, 159, 37–138.Google Scholar
- Lenz, A. C., & Johnson, B. D. (1985). Brachiopods of the Garra Formation (Lower Devonian), Wellington area, New South Wales, Australia: Rhynchonellida, Spiriferida, Terebratulida. Palaeontographica Abteilung A, 188(4–6), 71–104.Google Scholar
- Liao, W. H., & Ma, X. P. (2011). On the Givetian transgression in South China and the Endophyllum–bearing beds——with a comparison of Endophyllum from S–China and “Endophyllum” from N–Xinjiang. Acta Palaeontologica Sinica, 50(1), 64–76 [in Chinese with English abstract].Google Scholar
- Liao, W. H., Xu, H. K., Wang, C. Y., Ruan, Y. P., Cai, C. Y., Mu, D. C., & Lu, L. C. (1978). Subdivision and correlation of the Devonian strata in southwestern China. In Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences (Ed.), Symposium on the Devonian System of South China (pp. 193–213). Beijing: Geological Publishing House in Chinese.Google Scholar
- Liao, W. H., Xu, H. K., Wang, C. Y., Cai, C. Y., Ruan, Y. P., Mu, D. C., & Lu, L. C. (1979). On some basic Devonian sections in southwestern China. In Nanjing Institute of Geology and Palaeontology (Ed.), Carbonate biostratigraphy in southwestern regions (pp. 221–249). Beijing: Science Press [in Chinese].Google Scholar
- Liao, W. H., Ma, X. P., & Sun, Y. L. (2006). Some Devonian rugose corals from Panxi, Huaning County, Yunnan Province. Earth Science Frontiers, 13(6), 234–246.Google Scholar
- Liashenko, A. I. (1969). Novye Devonskie brakhiopody tsentral’nykh i zapadnykh raionov Russkoi Platformy [New Devonian brachiopods from the central and western areas of the Russian Platform]. Ministerstvo Geologii SSSR, Vsesoiuznyi Nauchno–Issledovatel’skii Geologo–Razvedochnyi Neftianoi Institut (VNIGNI) Trudy, 93, 9–27 5 pl.Google Scholar
- Lü, D. (2017). Late Frasnian to Famennian (Late Devonian) brachiopods of central Hunan, South China. Peking University, Doctoral dissertation [in Chinese with English abstract].Google Scholar
- Ma, X. P. (1995). The type species of the brachiopod Yunnanellina from the Devonian of South China. Palaeontology, 38(2), 385–405.Google Scholar
- Ma, X. P. (2009). Spiriferide brachiopods from the Frasnian (Devonian) of the Dushan area, southern Guizhou, China. Acta Palaeontologica Sinica, 48(4), 611–627.Google Scholar
- Ma, X. P., Bai, Z. Q., Sun, Y. L., Zhang, Y. B., & Wang, J. H. (2004). Lithologic and biostratigraphic aspects of the Shetianqiao section, the stratotype section for the Upper Devonian Shetianqiao Stage of Chinas. Professional Papers of Stratigraphy and Palaeontology, 28, 89–110 [in Chinese with English abstract].Google Scholar
- Ma, X. P., Becker, R. T., Li, H., & Sun, Y. Y. (2006). Early and Middle Frasnian brachiopod faunas and turnover on the South China shelf. Acta Palaeontologica Polonica, 51(4), 789–812.Google Scholar
- Ma, Y. S., Chen, H. D., & Wan, G. L. (2009b). Sequence stratigraphy and palaeogeography of the South China. Beijing: Science Press [in Chinese].Google Scholar
- Ma, X. P., Gong, Y. M., Chen, D. Z., Racki, G., Chen, X. Q., & Liao, W. H. (2016). The Late Devonian Frasnian–Famennian Event in South China—patterns and causes of extinctions, sea level changes, and isotope variations. Palaeogeography, Palaeoclimatology, Palaeoecology, 448, 224–244.CrossRefGoogle Scholar
- Ma, X. P., Wang, H. H., & Zhang, M. Q. (2017). Devonian event succession and sea level change in South China—with Early and Middle Devonian carbon and oxygen isotopic data. Subcommission on Devonian Stratigraphy, Newsletter, 32, 17–24.Google Scholar
- Mergl, M. (2003). Silicified brachiopods of the Kotýs Limestone (Lochkovian) in the Bubovice area (Barrandian, Bohemia). Acta Musei Nationalis Pragae, Series B, Natural History, 59(3–4), 99–150.Google Scholar
- Mergl, M., & Massa, D. (1992). Devonian and Lower Carboniferous brachiopods and bivalves from western Libya. Biostratigraphie du Paleozoique, 12, 1–115.Google Scholar
- Michels, D. (1986). Ökologie und Fazies des jüngsten Ober-Devon von Velbert (Rheinisches Schiefergebirge). Göttinger Arbeiten zur Geologie und Palaeontologie, 29, 1–86.Google Scholar
- Morales, P. A. (1965). A contribution to the knowledge of the Devonian faunas of Colombia. Boletin de Geologia, 19, 51–111.Google Scholar
- Mottequin, B. (2008). New observations on Upper Devonian brachiopods from the Namur-Dinant Basin (Belgium). Geodiversitas, 30(3), 455–537.Google Scholar
- Nalivkin, D. V. (1941). Brachiopods of the main Devonian field. Akademia Nauk SSSR, Trudy, 1, 139–226.Google Scholar
- Norris, A. W., & Uyeno, T. T. (1998). Middle Devonian brachiopods, conodonts, stratigraphy, and transgressive–regressive cycles, Pine Point area, south of Great Slave Lake, District of Mackenzie, Northwest Territories. Geological Survey of Canada Bulletin, 522, 1–191.Google Scholar
- Norris, A. W., Uyeno, T. T., Sartenaer, P., & Telford, P. G. (1992). Brachiopod and conodont faunas from the uppermost Williams Island Formation and lower Long Rapids Formation (Middle and Upper Devonian), Moose River Basin, northern Ontario. Geological Survey of Canada Bulletin, 434, 1–133.Google Scholar
- Paulus, B. (1957). Rhynchospirifer n. gen. im Rheinischen Devon (Rhynchospiriferinae n. subf., Brachiopoda). Senckenbergiana lethaea, 38(1/2), 49–72.Google Scholar
- Perry, D. G. (1979). Late Early Devonian reef associated brachiopods of the Prongs Creek Formation, northern Yukon. Journal of Paleontology, 53(5), 1094–1111.Google Scholar
- Perry, D. G. (1984). Brachiopoda and biostratigraphy of the Silurian–Devonian Delorme Formation in the District of Mackenzie. Royal Ontario Museum, Life Sciences Contributions, 138, 1–243.Google Scholar
- Pitrat, C. W. (1965). Spiriferidina. In R. C. Moore (Ed.), Treatise on invertebrate paleontology. Part H, Brachiopoda (pp. 667–728). New York: Geological Society of America et University of Kansas Press.Google Scholar
- Racki, G. (1992). Brachiopod assemblages in the Devonian Kowala Formation of the Holy Cross Mountains. Acta Palaeontologica Polonica, 37, 297–357.Google Scholar
- Robinson, G. D. (1963). Geology of the Three Forks Quadrangle, Montana. United States Geological Survey Professional Paper, 370, 1–143.Google Scholar
- Rzhonsnitskaia, M. A. (1955). Brakhiopodi nizhnego i srednego devona Kuzbassa [Brachiopods of the lower and middle Devonian of the Kuzbass]. In L. L. Khalfin (Ed.), Atlas rukovodiashchikh form iskopaemikh fauni i flori zapadnoi Sibiri, vol. 1 (pp. 244–256; pl. 53–58, 63). Moscow: Gosgeoltekhizdat.Google Scholar
- Sanchez, T. M., & Benedetto, J. L. (1983). Paleoecologia, comunidades bentonicas y sucesion paleoambiental en el Grupo Rio Cachiri, Devonico, Sierra de Perija, Venezueal. Ameghiniana, 20(3–4), 163–198.Google Scholar
- Sandford, A., & Norris, F. (1975). Devonian strata of the Hudson Platform. Canadian Geological Survey Memoirs, 379, 1–124.Google Scholar
- Sapelnikov, V. P., Snigireva, M. P., Bikbayev, A. Z., & Mizens, L. I. (1995). Zonal subdivision of Early–Middle Devonian reef deposits of the Urals based on conodonts and brachiopods. Courier Forschungsinstitut Senckenberg, 182, 399–419.Google Scholar
- Savage, N. M. (1974). The brachiopods of the Lower Devonian Maradana Shale, New South Wales. Palaeontographica Abteilung A, 146(1–3), 1–51.Google Scholar
- Scotese, C. R. (2014a). Atlas of Silurian and Middle–Late Ordovician paleogeographic maps, maps 73–80, volumes 5, the Early Paleozoic. Evanston: PALEOMAP Atlas for ArcGIS, PALEOMAP Project.Google Scholar
- Scotese, C. R. (2014b). Atlas of Devonian paleogeographic maps, maps 65–72, volume 4, the Late Paleozoic. Evanston: PALEOMAP Atlas for ArcGIS, PALEOMAP Project.Google Scholar
- Sun, Y. L. (1992). Fossil brachiopods from Eifelian–Givetian boundary bed of Liujing Section, Guangxi, China. Acta Palaeontologica Sinica, 31, 708–723 in Chinese with English abstract.Google Scholar
- Telford, P. G. (1988). Devonian stratigraphy of the Moose River Basin, James Bay Lowland, Ontario, Canada. In N. J. McMillan, A. F. Embry, & D. J. Glass (Eds.), Devonian of the world, volume I (pp. 123–132). Calgary: Canadian Society of Petroleum Geologists.Google Scholar
- Tiazheva, A. P. (1960). Novye vidy Devonskikh retikuliariin Urala [New species of Devonian reticulariids from the Urals]. In B. P. Markowski (Ed.), Novye vidy drevnikh rastenii i bespozvonochnykh SSSR, part 1 [New species of ancient plants and invertebrates of the USSR ] (pp. 406–409). Moscow: VSEGEI.Google Scholar
- Tien, C. C. (1938). Devonian Brachiopoda of Hunan. Palaeontologia Sinica, new series B, 4, 1–192.Google Scholar
- Veevers, J. J. (1959a). Devonian brachiopods from the Fitzroy Basin, Western Australia. Australia, Bureau of Mineral Resources, Geology and Geophysics, Bulletin, 45, 1–220 pl. 1–18.Google Scholar
- Veevers, J. J. (1959b). The type species of Productella, Emanuella, Crurithyris and Ambocoelia (Brachiopoda). Journal of Paleontology, 33(5), 902–908.Google Scholar
- Vogel, K., Xu, H. K., & Langenstrassen, F. (1989). Brachiopods and their relation to facies development in the lower and Middle Devonian of Nandan, Guangxi, South China. Courier Forschungsinstitut Senckenberg, 110, 17–59.Google Scholar
- Wang, C. W., & Yang, S. P. (1998). A biostratigraphical study of the early Early Devonian brachiopods from Yulin, Guangxi. Journal of Stratigraphy, 22(3), 176–184.Google Scholar
- Wang, Y., & Zhu, R. F. (1979). Beiliuan (middle Middle Devonian) brachiopods from south Guizhou and central Guangxi. Palaeontologia Sinica series B, 158(15), 1–106 [in Chinese].Google Scholar
- Wang, Y., Liu, D. Y., Wu, Q., & Zhong, S. L. (1974). Brachiopoda. In Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (Ed.), Handbook of stratigraphy and paleontology in southwestern regions (pp. 240–247). Beijing: Science Press [in Chinese].Google Scholar
- Wang, G. X., Jing, Y. J., Zhuang, J. L., Zhang, C. F., & Hu, W. Q. (1986). Stratigraphical system of Devonian–Lower Carboniferous Epoch of Xikuangshan area in central region of Hunan. Hunan Geology, 5(3), 48–65 5(4), 36–50 [in Chinese with English abstract].Google Scholar
- Xian, S. Y. (1983). On the characteristics, member, geological age and geographical distribution of Rhynchospiriferidae (Brachiopoda). Papers of Stratigraphy and Paleontology of Guizhou, 1, 1–32 [in Chinese with English abstract].Google Scholar
- Xian, S. Y. (1998). The silicified brachiopod fossils from the base of the Mintang Formation (Middle Devonian) in Liujing, Guangxi. Lithofacies Paleogeography, 18(5), 28–56 [in Chinese with English abstract].Google Scholar
- Xian, S. Y., & Jiang, Z. L. (1978). Brachiopoda. In Guizhou Working Group of Stratigraphy and Paleontology (Ed.), Paleontological paleontological atlas of southwestern China, Guizhou (Kweichow) province (Cambrian–Devonian), vol. 1 (pp. 251–337). Beijing: Geological Publishing House [in Chinese].Google Scholar
- XIGMR (Xi’an Institute of Geology and Mineral Resources), & NIGP (Nanjing Institute of Geology and Palaeontology, Academia Sinica). (1987). Late Silurian–Devonian strata and fossils from Luqu–Tewo area of West Qinling Mountains, China, vol. 1, vol. 2. Nanjing: Nanjing University Press [in Chinese with English abstract and plates].Google Scholar
- Xu, H. K. (1979). Brachiopods from the Tangxiang Formation (Devonian) in Nandan of Guangxi. Acta Palaeontologica Sinica, 18(4), 362–380 [in Chinese with English abstract].Google Scholar
- Xu, Q. J., Wan, Z. Q., & Chen, Y. R. (1978). Brachiopoda. In Southwest Institute of Geological Science (Ed.), Palaeontological atlas of southwestern China, Sichuan volume, part 1 (pp. 284–381). Beijing: Geological Publishing House [in Chinese].Google Scholar
- Yang, D. L., Ni, S. Z., Chang, M. L., & Zhao, R. X. (1977). Brachiopoda. In Hubei Institute of Geological Sciences and others (Ed.), Paleontological atlas of central–South China, vol. 2 (late Paleozoic part) (pp. 306–470). Beijing: Geological Publishing House [in Chinese].Google Scholar
- Yolkin, E. A., Gratsianova, R. T., Bakharev, N. K., Izokh, N. E., Yazikov, A. Y., V'yushkova, L. V., Zheltonogova, V. A., & Petrosyan, N. M. (1988). Facies and faunal associations of the Telengitian (Emsian) in its type locality. In N. J. McMillan, A. F. Embry, & D. J. Glass (Eds.), Devonian of the world, volume III (pp. 193–207). Calgary: Canadian Society of Petroleum Geologists.Google Scholar
- Yolkin, E. A., Talent, J. A., Kipriyanova, T. P., Yolkina, V. N., Gratsianova, R. T., Shcherbanenko, T. A., & Kipriyanov, A. A. (2011). Biogeography of the Early Devonian brachiopods from north Eurasia. Novosti paleontologii i stratigrafii [News of paleontology and stratigraphy], 15, 103–147.Google Scholar
- Yu, C. M. (1988). Devonian–carboniferous boundary in Nanbiancun, Guilin, China—aspects and records. Beijing: Science Press.Google Scholar
- Yudina, Y. A., & Rzhonsnitskaya, M. A. (1985). Brachiopods from the Afoninsk Devonian horizon from the western slope of the Urals. In M. A. Kamalet-Dinov & M. A. Rzhonsnitskaya (Eds.), Srednij Devon SSSR, Ego Granitsy i Yarusnoe Raschlenenije (pp. 74–83). Moscow: Nauka [in Russian].Google Scholar
- Zhang, N. (1989a). Wenlockian (Silurian) brachiopods of the Cape Phillips Formation, Baillie Hamilton Island, Arctic Canada: part I. Palaeontographica Abteilung A, 206, 49–97.Google Scholar
- Zhang, N. (1989b). Wenlockian (Silurian) brachiopods of the Cape Phillips Formation, Baillie Hamilton Island, Arctic Canada: part III. Palaeontographica A, 207, 1–48.Google Scholar
- Zhang, N. (1991). Taxonomy, paleoecology, and paleobiogeography of Wenlockian (Silurian) brachiopods of the Cape Phillips formation from Baillie Hamilton Island, Arctic Canada. Oregon State University, Doctoral dissertation.Google Scholar
- Zhang, M. Q. (2016). Middle-Upper Devonian boundary: geochemical characteristics, brachiopod fauna and their stratigraphic significance. Peking University, Doctoral dissertation [in Chinese with English abstract].Google Scholar
- Zhang, Y., Fu, L. P., Ding, P. Z., & Qi, W. T. (1983). Brachiopoda (Late Palaeozoic Part). In Xi’an Institute of Geology and Mineral Resources (Ed.), Paleontological atlas of Northwest China, volume of Shaanxi, Gansu and Ningxia, part 2 (pp. 244–425). Beijing: Geological Publishing House [in Chinese].Google Scholar
- Zhang, Y. Z., Zhang, D. H., Liu, S. R., Xue, G. A., Huang, M. Q., Yang, Z. R., Peng, H. Z., Li, Y., Zhang, S. H., & He, T. Q. (1996). Lithostratigraphy of Yunnan province. Wuhan: China University of Geosciences press [in Chinese].Google Scholar
- Zhang, M. Q., Ma, X. P., & Zhang, Y. B. (2015). Leiorhynchid brachiopods across the middle–upper Devonian boundary in South China. Acta Palaeontologica Sinica, 54(4), 481–500 [in Chinese with English abstract].Google Scholar