Skip to main content Accessibility help
×
Home

Palate and braincase of Whatcheeria deltae Lombard & Bolt, 1995

  • John R. BOLT (a1) and R. Eric LOMBARD (a2)

Abstract

The reconstructed palate of Whatcheeria deltae indicates a skull that was unusually narrow: at least 2.2 times longer than wide if the pterygoids are conservatively placed in the horizontal plane. This maximum width is narrower than any other early tetrapod reconstructed so far. Rotating the pterygoids to produce a vaulted palate would produce an even narrower skull. Primitive palatal features include very narrow interpterygoid vacuities and a vomer, palatine, and ectopterygoid with fang-sized replacement pairs. It is derived in that there is no anterior palatal fenestra and the premaxilla has a substantial palatal shelf – a combination of characters shared only with Proterogyrinus among early tetrapods. There is a possible septomaxilla in one specimen. Whatcheeria differs from and is more derived than Pederpes, its likely sister taxon, in that only the pterygoid is covered with denticles, the vomer, palatine, and ectopterygoid containing labyrinthine teeth only. Reconstructed dental occlusion indicates that the large choana apparently accommodated the large dentary fangs; this would be a unique feature among early tetrapods. The palatal ramus of the pterygoid is longer than the quadrate ramus, which does not have a descending flange. Like Meckel's cartilage in the lower jaw, the palatoquadrate is fully ossified in larger specimens, such that in a posterior view of the skull the pterygoid is mostly hidden from sight by the epipterygoid. The ossified neurocranium consists of the basiparasphenoid and basioccipital; no ossified sphenethmoid has been found. Remains of otic capsules are partial, crushed, and smeared, so no useful morphology is available. The stapes appears to be more columnar and less plate-like than in many other primitive, early tetrapods.

Copyright

Corresponding author

*Corresponding author

References

Hide All
Bolt, J. R. & Lombard, R. E. 1985. Evolution of the amphibian tympanic ear and the origin of frogs. Biological Journal of the Linnean Society 24, 8399.
Bolt, J. R. & Lombard, R. E. 2000. Palaeobiology of Whatcheeria deltae, a primitive Mississippian tetrapod. In Heatwole, H. (ed.) Amphibian biology, 4, Paleobiology, 10441052. Chipping Norton, Australia: Surrey Beatty and Sons.
Carroll, R. L. 1980. The hyomandibular as a supporting element in the skull of primitive tetrapods. In Panchen, A. L. (ed.) The terrestrial environment and the origin of land vertebrates, 293317. London: Academic Press.
Clack, J. A. 1983. The stapes of the Coal Measures embolomere Pholiderpeton scutigerum Huxley (Amphibia: Anthracosauria) and otic evolution in early tetrapods. Zoological Journal of the Linnean Society 79, 121148.
Clack, J. A. 1987. Pholiderpeton scutigerum Huxley, an amphibian from the Yorkshire Coal Measures. Philosophical Transactions of the Royal Society of London, Series B 318, 1–107.
Clack, J. A. 1989. Discovery of the earliest-known tetrapod stapes. Nature 342, 425427.
Clack, J. A. 1992. The stapes of Acanthostega gunnari and the role of the stapes in early tetrapods. In Webster, D. B., Fay, R. R. & Popper, A. (eds) The evolutionary biology of hearing, 405420. New York: Springer-Verlag.
Clack, J. A. 1994. Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance. Meddelelser om Grønland: Geoscience 31, 124.
Clack, J. A. 1998. The Scottish Carboniferous tetrapod Crassigyrinus scoticus (Lydekker) – cranial anatomy and relationships. Transactions of the Royal Society of Edinburgh: Earth Sciences 88, 127142.
Clack, J. A. 2002a. An early tetrapod from ‘Romer's Gap'. Nature 418, 7276.
Clack, J. A. 2002b. The dermal skull roof of Acanthostega gunnari, an early tetrapod from the Late Devonian. Transactions of the Royal Society of Edinburgh: Earth Sciences 93, 1733.
Clack, J. A. 2003a. A new baphetid (stem tetrapod) from the Upper Carboniferous of Tyne and Wear, U. K., and the evolution of the tetrapod occiput. Canadian Journal of Earth Sciences 40, 483498.
Clack, J. A. 2003b. A revised reconstruction of the dermal skull roof of Acanthostega gunnari, an early tetrapod from the Late Devonian. Transactions of the Royal Society of Edinburgh: Earth Sciences 93, 163165.
Clack, J. A., Ahlberg, P. E., Finney, S. M., Dominguez Alonso, P., Robinson, J. & Ketcham, R. A. 2003. A uniquely specialized ear in an early tetrapod. Nature 425, 6569.
Clack, J. A., Witzmann, F., Müller, J. & Snyder, D. 2012. A colosteid-like early tetrapod from the St. Louis Limestone (Early Carboniferous, Meramecian), St. Louis, Missouri, USA. Fieldiana Life and Earth Sciences 5, 1739.
Clack, J. A., Bennett, C. E., Carpenter, D. K., Davies, S. J., Fraser, N. C., Kearsey, T. I., Marshall, J. E. A., Millward, D., Otoo, B. K. A., Reeves, E. J., Ross, A. J., Ruta, M., Smithson, K. Z., Smithson, T. R. & Walsh, S. A. 2016. Phylogenetic and environmental context of a Tournaisian tetrapod fauna. Nature Ecology and Evolution 1, 0002.
Clack, J. A. & Finney, S. M. 2005. Pederpes finneyae, an articulated tetrapod from the Tournaisian of Western Scotland. Journal of Systematic Palaeontology 2, 311346.
Clack, J. A. & Holmes, R. 1988. The braincase of the anthracosaur Archeria crassidisca with comments on the interrelationships of primitive tetrapods. Palaeontology 31, 85107.
Daeschler, E. B., Shubin, N. H. & Jenkins, F. A. Jr. 2006. A Devonian tetrapod-like fish and the evolution of the tetrapod body plan. Nature 440, 757763.
Goodrich, E. S. 1958. Studies on the structure and development of vertebrates, I, i–lxix + 485 pp. New York: Dover Publications Inc.
Holmes, R. 1984. The carboniferous amphibian Proterogyrinus scheelei Romer, and the early evolution of tetrapods. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 306, 431524.
Holmes, R. 1989. The skull and axial skeleton of the Lower Permian anthracosauroid amphibian Archeria crassidisca. Palaeontographica, Abteilung A 207, 161206.
Huttenlocker, A. K., Pardo, J. D., Small, B. J. & Anderson, J. S. 2013. Cranial morphology of Recumbirostrans (Lepospondyli) from the Permian of Kansas and Nebraska, and early morphological evolution inferred by micro-computed tomography. Journal of Vertebrate Paleontology 33, 540552.
Jarvik, E. 1954. On the visceral skeleton in Eusthenopteron with a discussion of the parasphenoid and palatoquadrate in fishes. Kungliga Svenska Vetenskapsakademiens Handlingar 5, 1–104.
Jarvik, E. 1972. Middle and Upper Devonian porolepiformes from East Greenland with special reference to Glyptolepis groenlandica n. sp. Meddeleser Om Gronland 187(2), 1–307+35 pls.
Jarvik, E. 1980. Basic structure and evolution of vertebrates. Vol. 1. 575 pp. London: Academic Press.
Jarvik, E. 1996. The Devonian tetrapod Ichthyostega. Fossils and Strata series 40. Oslo: Scandinavian University Press.
Kimmel, C. B., Sidlauskas, B. & Clack, J. A. 2009. Linked morphological changes during palate evolution in early tetrapods. Journal of Anatomy 215, 91109.
Lombard, R. E. & Bolt, J. R. 1995. A new primitive tetrapod, Whatcheeria deltae, from the Lower Carboniferous of Iowa. Palaeontology 38, 471491.
Lombard, R. E. & Bolt, J. R. 2006. The mandible of Whatcheeria deltae, an early tetrapod from the Late Mississippian of Iowa. In Carrano, M. T., Gaudin, T. J., Blob, R. W. & Wi, J. R. (eds) Perspectives on the evolution of mammals, birds, and reptiles, 2152. Chicago: University of Chicago Press.
Maddin, H. C. & Anderson, J. S. 2012. Evolution of the amphibian ear with implications for lissamphibian phylogeny: insight gained from the caecilian inner ear. Fieldiana Life and Earth Sciences 5, 5976.
Panchen, A. L. 1972. The skull and skeleton of Eogyrinus attheyi Watson (Amphibia: Labyrinthodontia). Philosophical Transactions of the Royal Society of London, B 263, 279326.
Panchen, A. L. 1985. On the Amphibian Crassigyrinus scoticus Watson from the Carboniferous of Scotland. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 309, 505568.
Pardo, J. D., Szostakiwskyj, M., Ahlberg, P. E. & Anderson, J. S. 2017. Hidden morphological diversity among early tetrapods. Nature 546, 642645.
Robinson, J., Ahlberg, P. E. & Koentges, G. 2005. The braincase and middle ear region of Dendrerpeton acadianum (Tetrapoda: Temnospondyli). Zoological Journal of the Linnean Society 143, 577597.
Romer, A. S. & Witter, R. V. 1942. Edops, a primitive rhachitomous amphibian from the Texas red beds. Journal of Geology 50, 925960.
Sawin, H. J. 1941. The cranial anatomy of Eryops megacephalas. Bulletin of the Museum of Comparative Zoology, Harvard 88, 407463.
Sigurdsen, T. & Green, D. M. 2011. The origin of modern amphibians: a re-evaluation. Zoological Journal of the Linnean Society 162, 457469.
Smithson, T. R. 1982. The cranial morphology of Greererpeton burkemorani Romer (Amphibia: Temnospondyli). Zoological Journal of the Linnean Society 76, 2990.
Snyder, D. 2006. A study of the fossil vertebrate fauna from the Jasper Hiemstra quarry, Delta, Iowa, and its environment. PhD Thesis, University of Iowa, IA, USA. 180 pp.
Warren, A. 2007. New data on Ossinodus pueri, a stem tetrapod from the Early Carboniferous of Australia. Journal of Vertebrate Paleontology 27, 850862.
Witzke, B. J., McKay, R. M., Bunker, B. J. & Woodson, F. J. 1990. Stratigraphy and paleoenvironments of Mississippian strata in Keokuk and Washington Counties, southeast Iowa. Guidebook Series 10, 1–105. Iowa City: Iowa Department of Natural Resources.

Keywords

Type Description Title
WORD
Supplementary materials

Bolt and Lombard supplementary material
Appendix

 Word (37 KB)
37 KB

Palate and braincase of Whatcheeria deltae Lombard & Bolt, 1995

  • John R. BOLT (a1) and R. Eric LOMBARD (a2)

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed