Baptanodon

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Baptanodon
Temporal range: Late Jurassic, 160–156 Ma
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Gilmore Notes on Osteology of Baptanodon Plate XXXVI.png
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: †Ichthyosauria
Family: †Ophthalmosauridae
Subfamily: †Ophthalmosaurinae
Genus: †Baptanodon
Marsh, 1880
Type species
†Baptanodon natans
Marsh, 1880
Synonyms
  • Ophthalmosaurus natans Marsh, 1879
  • Sauranodon Marsh, 1879 (preoccupied)
  • Microdontosaurus Gilmore, 1902

Baptanodon is an ichthyosaur of the Late Jurassic period (160-156 million years ago), named for its extremely large eyes. It had a graceful 6 m (19.5 ft) long dolphin-shaped body, and its almost toothless jaw was well adapted for catching squid. Major fossil finds of this genus have been recorded in North America. The type species, Sauranodon natans, was originally included under Sauranodon in 1879,[1] but this name was preoccupied.

Discovery and species[]

Baptanodon is a replacement name for Sauranodon applied to ichthyosaur material in 1879[1] and was moved to its own genus Baptanodon in 1880 when Sauranodon was found to be preoccupied.[2] Baptanodon was considered a junior synonym of Ophthalmosaurus by Maisch & Matzke (2000).[3] However, cladistic analyses published in the 2010s indicate that Baptanodon is not congeneric with Ophthalmosaurus icenicus.[4][5][6]

Classification[]

The cladogram below follows Fischer et al. 2012.[5]

Thunnosauria 
 

Ichthyosaurus

 
 
 

Stenopterygius

 
 
 

Chacaicosaurus

 
 Ophthalmosauridae 
 

Arthropterygius

 
*
 Ophthalmosaurinae 
 

Mollesaurus

 
 
 

Ophthalmosaurus

 
 
 

Baptanodon

 
 

Acamptonectes

 
 
 
 
 Platypterygiinae 
 
 

Brachypterygius

 
 
 

Maiaspondylus

 
 
 

Aegirosaurus

 
 

Sveltonectes

 
 
 
 
 
 

"Platypterygius" hercynicus

 
 
 

Caypullisaurus

 
 
 

Athabascasaurus

 
 

"Platypterygius" australis (=Longirostria)[7]

 
 
 
 
 
 
 
 
 
 

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.[2][8]

See also[]

References[]

  1. ^ a b 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
  2. ^ a b Marsh, O. C., 1880, Note on Sauranodon: American Journal of Science, 3rd series, v. 19, n. 4, p. 491.
  3. ^ Maisch MW, Matzke AT. 2000. The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie) 298: 1-159.
  4. ^ Patrick S. Druckenmiller and 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. Bibcode:2010CaJES..47.1037D. doi:10.1139/E10-028.CS1 maint: uses authors parameter (link)
  5. ^ a b Valentin Fischer; et al. (2012). "New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary". PLOS ONE. 7 (1): e29234. Bibcode:2012PLoSO...729234F. doi:10.1371/journal.pone.0029234. PMC 3250416. PMID 22235274.
  6. ^ 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.
  7. ^ Arkhangel’sky, M. S., 1998, On the Ichthyosaurian Genus Platypterygius: Palaeontological Journal, v. 32, n. 6, p. 611-615.
  8. ^ Marsh, O. C., 1895, The Reptilia of the Baptanodon Beds: American Journal of Science, 3rd series, v. 34., n. 299, p. 405-406.
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