Skip to main content
SpringerLink
Log in

Grooves to tubes: evolution of the venom delivery system in a Late Triassic “reptile”

  • Short Communication
  • Published:
Naturwissenschaften Aims and scope Submit manuscript

Abstract

Venom delivery systems occur in a wide range of extant and fossil vertebrates and are primarily based on oral adaptations. Teeth range from unmodified (Komodo dragons) to highly specialized fangs similar to hypodermic needles (protero- and solenoglyphous snakes). Developmental biologists have documented evidence for an infolding pathway of fang evolution, where the groove folds over to create the more derived condition. However, the oldest known members of venomous clades retain the same condition as their extant relatives, resulting in no fossil evidence for the transition. Based on a comparison of previously known specimens with newly discovered teeth from North Carolina, we describe a new species of the Late Triassic archosauriform Uatchitodon and provide detailed analyses that provide evidence for both venom conduction and document a complete structural series from shallow grooves to fully enclosed tubular canals. While known only from teeth, Uatchitodon is highly diagnostic in possessing compound serrations and for having two venom canals on each tooth in the dentition. Further, although not a snake, Uatchitodon sheds light on the evolutionary trajectory of venom delivery systems in amniotes and provide solid evidence for venom conduction in archosaur-line diapsids.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

References

  • Bogert CM (1943) Dentitional phenomena in cobras and other elapids with notes on adaptive modifications of fangs. Bull Am Mus Nat Hist 81:285–360

    Google Scholar 

  • Currie PJ, Rigby JK, Sloan RE (1990) Theropod teeth from the Judith River Formation of Southern Alberta, Canada. In: Carpenter K, Currie PJ (eds) Dinosaur systematics: approaches and perspectives. Cambridge University Press, Cambridge, pp 107–125

    Chapter  Google Scholar 

  • Folinsbee KE, Müller J, Reisz RR (2007) Canine grooves: morphology, function and relevance to venom. J Vertebr Paleont 27:547–551

    Article  Google Scholar 

  • Fry BG, Vidal N, Norman JA, Vonk FJ, Scheib H, Ramjan R, Kuruppu S, Fung K, Hedges SB, Richardson MK, Hodgson WC, Ignjatovic V, Summerhayes R, Kochva E (2006) Early evolution of the venom system in lizards and snakes. Nature 439:509–632

    Article  Google Scholar 

  • Fry BG, Scheib H, van der Weerd L, Young B, McNaughtan J, Ramjan SFR, Vidal N, Poelmann RE, Norman JA (2008) Evolution of an arsenal: structural and functional diversification of the venom system in the advanced snakes (Caenophidia). Mol Cell Proteomics 7:215–246

    CAS  PubMed  Google Scholar 

  • Fry BG, Wroe S, Teeuwisse W, van Osch MJP, Moreno K, Ingle J, McHenry C, Ferrara T, Clausen P, Scheib H, Winter KL, Greisman L, Roelants K, van der Weerd L, Clemente CJ, Giannakis E, Hodgson WC, Luz S, Martelli P, Krishnasamy K, Kochva E, Kwok HF, Scanlon D, Karas J, Citron DM, Goldstein EJC, Mcnaughtan JE, Norman JA (2009) A central role for venom in predation by Varanus komodoensis (Komodo dragon) and the extinct giant Varanus (Megalania) prisca. Proc Nat Acad Sci USA 106:8969–8974

    Article  CAS  PubMed  Google Scholar 

  • Gianechini F, Agnolín F, Ezcurra M (2010) A reassessment of the purported venom delivery system of the bird-like raptor Sinornithosaurus. Paläont Z (Early view) doi:10.1007/s12542-010-0074-9

  • Godefroit P, Cuny G (1997) Archosauriform teeth from the Upper Triassic of Saint-Nicolas-de-Port (northeastern France). Palaeovertebrata 26:1–34

    Google Scholar 

  • Gong E, Martin LD, Burnham DA, Falk AR (2010) The birdlike raptor Sinornithosaurus was venomous. Proc Nat Acad Sci USA 107:766–768

    Article  CAS  PubMed  Google Scholar 

  • Heckert AB (2004) Late Triassic microvertebrates from the lower Chinle Group (Otischalkian–Adamanian: Carnian), Southwestern U.S.A. Bull New Mex Mus Nat Hist Sci 27:1–170

    Google Scholar 

  • Hungerbühler A (2000) Heterodonty in the European phytosaur Nicrosaurus kapffi and its implications for the taxonomic utility and functional morphology of phytosaur dentitions. J Vertebr Paleontol 20:31–48

    Article  Google Scholar 

  • Jackson K (2002) How tubular venom-conducting fangs are formed. J Morph 252:291–297

    Article  PubMed  Google Scholar 

  • Kaye FT, Padian K (1994) Microvertebrates from the Placerias Quarry: a window on Late Triassic vertebrate diversity in the American Southwest. In: Fraser NC, Sues H-D (eds) In the shadow of the dinosaurs: early Mesozoic tetrapods. Cambridge University Press, Cambridge, pp 171–196

    Google Scholar 

  • Kochva E (1987) The origin of snakes and evolution of the venom apparatus. Toxicon 25:65–106

    Article  CAS  PubMed  Google Scholar 

  • Kuch U, Müller J, Modden C, Mebs D (2006) Snake fangs from the Lower Miocene of Germany: evolutionary stability of perfect weapons. Naturwissenschaften 93:84–87

    Article  CAS  PubMed  Google Scholar 

  • Lucas SG, Heckert AB, Hunt AP (1997) Lithostratigraphy and biostratigraphic significance of the Placerias quarry, east-central Arizona. Neues Jb Geol Paläontol Abh 203:23–46

    Google Scholar 

  • Nydam RL (2000) A new taxon of helodermatid-like lizard from the Albian-Cenomanian of Utah. J Vertebr Paleontol 20:285–294

    Article  Google Scholar 

  • Orr CM, Delezene LK, Scott JE, Tocheri MW, Schwartz GT (2007) The comparative method and the inference of venom-delivery systems in fossil mammals. J Vertebr Paleontol 27:541–546

    Article  Google Scholar 

  • Reynoso V (2005) Possible evidence of a venom apparatus in a Middle Jurassic sphenodontian from the Huizachal red beds of Tamaulipas, Mexico. J Vertebr Paleontol 25:646–654

    Article  Google Scholar 

  • Sander PM (1999) The microstructure of reptilian tooth enamel: terminology, function, and phylogeny. Münchener Geowissenschafliche Abhandlungen Reihe A 38:1–102

    Google Scholar 

  • Smith WL, Wheeler WC (2006) Venom evolution widespread in fishes: a phylogenetic road map for the bioprospecting of piscine venoms. J Hered 97:206–217

    Article  CAS  PubMed  Google Scholar 

  • Sues H-D (1991) Venom-conducting teeth in a Triassic reptile. Nature 351:141–143

    Article  Google Scholar 

  • Sues H-D (1996) A reptilian tooth with apparent venom canals from the Chinle Group (Upper Triassic) of Arizona. J Vertebr Paleontol 16:571–572

    Article  Google Scholar 

  • Sues H-D, Hopson JA (2010) Anatomy and phylogenetic relationships of Boreogomphodon jeffersoni (Cynodontia: Gomphodontia) from the Upper Triassic of Virginia. J Vertebr Paleontol 30:1202–1220

    Article  Google Scholar 

  • Sues H-D, Olsen PE (1990) Triassic vertebrates of Gondwanan aspect from the Richmond basin of Virginia. Science 249:1020–1023

    Article  CAS  PubMed  Google Scholar 

  • Sues H-D, Olsen PE, Kroehler PA (1994) Small tetrapods from the Upper Triassic of the Richmond basin (Newark Supergroup), Virginia. In: Fraser NC, Sues H-D (eds) In the shadow of the dinosaurs: early Mesozoic tetrapods. Cambridge University Press, Cambridge, pp 161–170

    Google Scholar 

  • Szaniawski H (2009) The earliest known venomous animals recognized among conodonts. Acta Palaeontol Pol 54:669–676

    Article  Google Scholar 

  • Weems R, Olsen PE (1997) Revision and synthesis of groups within the Newark Supergroup, Eastern North America. Geol Soc Am Bull 109:195–209

    Article  Google Scholar 

Download references

Acknowledgments

We would like to acknowledge two anonymous reviewers for their helpful critiques and comments, as well as the North Carolina Museum of Natural Sciences field crew for excavating the Moncure locality, Liz Sues, Pete Kroehler, and Ken Pitt for assistance in the excavation of the Tomahawk locality and the Appalachian State University Department of Geology and Office of Student Research for travel and research grants.

Author information

Authors and Affiliations

  1. Committee on Evolutionary Biology, The University of Chicago, 1025 57th Culver 402, Chicago, IL, 60637, USA

    Jonathan S. Mitchell

  2. Department of Geology, ASU Appalachian State University, P.O. Box 32067, Boone, NC, 28608, USA

    Jonathan S. Mitchell & Andrew B. Heckert

  3. Department of Paleobiology, National Museum of Natural History, MRC 121, P.O. Box 37012, Washington, DC, 20013-7012, USA

    Hans-Dieter Sues

Authors
  1. Jonathan S. Mitchell
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Andrew B. Heckert
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Hans-Dieter Sues
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Jonathan S. Mitchell.

Electronic supplementary material

Below is the link to the electronic supplementary material.

ESM 1

(DOC 53 kb)

Figure S1

Measurements taken from the Moncure Uatchitodon specimens. The mesial carina is at top, and the lingual surface is to the right. See Table S1 for results. (JPEG 1209 kb)

Figure S2

Diagram showing gross morphology of venomous teeth of cobras (a–b) to U. schneideri (c–e). a, b Modified from Wüster and Thorpe (1992; Fig. 2) showing the aperture morphology of a spitting cobra fang (a) and a non-spitting cobra fang (b). c shows the Placerias Quarry specimen (MNA V3680) and d shows a putative premaxillary specimen from Moncure (NCSM 24753). e shows NCSM 24732, with arrows denoting the extent of the aperture. Note that all of the specimens of U. schneideri show an oval aperture with a shallow apical margin, reminiscent of the non-spitting cobra. Further, specimens with tips show a distinct mesiolabial curvature of the tooth apical to the aperture, similar to what is seen in many extant venomous snakes. The voucher specimens to the upper right of each diagram in Figure 2 are: A2-USNM542520, A3-USNM542523, A4-USNM542521, A5-NCSM 25238, A6-NCSM 25241, B1-USNM542524, B2-USNM542519, B3-USNM542518, B4-NCSM24753, B5-MNA3680. (JPEG 1330 kb)

Figure S3

Details of the morphology of Uatchitodon teeth. a Sectioned Uatchitodon tooth (NCSM 24731), with the surface of the tooth to the bottom right and a portion of the canal in the upper right, note the curvature of the incremental growth lines of dentine, suggesting a developmental origin for the canal. b A close-up of the serrations on NCSM 25252 (1) and MNA V3680 (2) from the Placerias Quarry; scale bars = 0.1 mm. c The sections of NCSM 24731 with apical to the right and the base of the tooth (1), the bottom of the first section (2), the top of the first section (3), and the bottom of the second section (4) all scaled to 0.5 mm. (JPEG 1734 kb)

Figure S4a

Graphs showing the Uatchitodon lateral compression data (a, b) and size-related data (c, d). Lateral compression of a U. schneideri and b U. kroehleri. c Plot of the ln of the distance from the tip as a function of the ln of tooth width (least-squares regression yields an R 2-ad = 0.97, p < 0.001) and d canal shape as a function of the fore-aft length and distance from the tip. (PDF 3 kb)

Figure S4b

(PDF 2 kb)

Figure S4c

(PDF 10 kb)

Figure S4d

(JPG 75 kb)

Table S3

(XLS 36 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Mitchell, J.S., Heckert, A.B. & Sues, HD. Grooves to tubes: evolution of the venom delivery system in a Late Triassic “reptile”. Naturwissenschaften 97, 1117–1121 (2010). https://doi.org/10.1007/s00114-010-0729-0

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00114-010-0729-0

Keywords

Search

Navigation