Baptanodon Explained

Baptanodon is an ichthyosaur of the Late Jurassic period (160-156 million years ago), named for its supposed lack of teeth (although teeth of this genus have since been discovered).^[1] It had a graceful 3.5m (11.5feet) long dolphin-shaped body, and its jaws were well adapted for catching squid.^[2] Major fossil finds of this genus have been recorded in North America. The type species, Sauranodon natans, was originally included under Sauranodon in 1879,^[3] but this name was preoccupied.

Discovery and species

Baptanodon is a replacement name for Sauranodon applied to ichthyosaur material in 1879 and was moved to its own genus Baptanodon in 1880 when Sauranodon was found to be preoccupied.Baptanodon was considered a junior synonym of Ophthalmosaurus by Maisch & Matzke (2000).^[4] However, cladistic analyses published in the 2010s indicate that Baptanodon is not congeneric with Ophthalmosaurus icenicus.^{[5] [6] [7]}

Classification

The cladogram below follows Fischer et al. 2012.^[6]

Palaeobiology

Fossils of Baptanodon have been found in the Oxfordian-age Sundance Formation of Wyoming, which also has yielded fossils of the cryptoclidids Tatenectes and Pantosaurus, and the pliosaurid Megalneusaurus.^{[8] [9]}

See also

• List of ichthyosaurs
• Timeline of ichthyosaur research

Notes and References

1. Gilmore. C. W.. 1902. Discovery of teeth in Baptanodon, an ichthyosaurian from the Jurassic of Wyoming. Science. 16. 414. 913–914. 10.1126/science.16.414.913 . 17756122 . 1902Sci....16..913G .
2. Massare. J.A.. Wahl. W.R.. Ross. M.. Connely. M.V.. 2014. Palaeoecology of the marine reptiles of the Redwater Shale Member of the Sundance Formation (Jurassic) of central Wyoming, USA. Geological Magazine. 151. 1. 167–182. 10.1017/S0016756813000472.
3. O. C. Marsh. 1879. A new order of extinct reptiles (Sauranodonta), from the Jurassic Formation of the Rocky Mountains. The American Journal of Science and Arts, series 3
4. Maisch MW, Matzke AT. 2000. The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie) 298: 1-159.
5. Patrick S. Druckenmiller . Erin E. Maxwell . 2010 . A new Lower Cretaceous (lower Albian) ichthyosaur genus from the Clearwater Formation, Alberta, Canada . Canadian Journal of Earth Sciences . 47 . 8 . 1037–1053 . 10.1139/E10-028 . 2010CaJES..47.1037D.
6. Valentin Fischer. 2012 . New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary . PLOS ONE . 7 . 1 . e29234 . 10.1371/journal.pone.0029234 . 22235274 . 3250416. etal. 2012PLoSO...729234F. free .
7. Ilaria Paparella; Erin E. Maxwell; Angelo Cipriani; Scilla Roncacè; Michael W. Caldwell (2017). "The first ophthalmosaurid ichthyosaur from the Upper Jurassic of the Umbrian–Marchean Apennines (Marche, Central Italy)". Geological Magazine. 154 (4): 837–858. doi:10.1017/S0016756816000455.
8. Marsh, O. C., 1880, Note on Sauranodon: American Journal of Science, 3rd series, v. 19, n. 4, p. 491.
9. Marsh, O. C., 1895, The Reptilia of the Baptanodon Beds: American Journal of Science, 3rd series, v. 34., n. 299, p. 405-406.