PROFILPELAJAR.COM

Bahndwivici; Temporal range: Eocene, 52-51 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	holotype
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Family:	Shinisauridae
Genus:	†Bahndwivici
Species:	†B. ammoskius
Binomial name
	†Bahndwivici ammoskius; Conrad, 2006

Bahndwivici is an extinct genus of lizard known from a nearly complete and articulated skeleton discovered in rocks of the Green River Formation of Wyoming, United States. The skeleton is very similar to that of the modern Chinese crocodile lizard, Shinisaurus.

Description

Bahndwicivi is based on FMNH PR2260, a skeleton collected from the Thompson Ranch Locality of the Fossil Butte Member of the Green River Formation. It was described in 2006 by Jack Conrad. The type species is B. ammoskius. The genus name means "handsome in the water" in Shoshoni, a reference both to the animal's possible semiaquatic lifestyle and to the Shoshone people who once lived in the area. The specific name is a combination of the Ancient Greek words for sandy (ammos) and shade (skia), referring to its habitat.^[1]

FMNH PR2260 is more or less complete, primarily lacking some bones from the rear of the skull. The skeleton is well-articulated, with numerous rows of osteoderms remaining in place beneath the tail, but is somewhat flattened. The animal appears to have been an adult when it died. It differs from Shinisaurus in a few details. For example, FMNH PR2260 had a proportionally longer snout and an additional tooth in the upper jaw, and its postorbital and postfrontal bones were not fused.^[1]

Paleoecology

Bahndwivici is one of several lizards known from the Fossil Butte Member of the Green River Formation. This rock unit represents part of Fossil Lake, the smallest and shortest-lived of three prehistoric lake systems that make up the Green River Formation.^[2] The lake sediments include a volcanic ash dating to 51.66 million years ago, during the Early Eocene.^[2] Fossils are abundant in the rocks of Fossil Lake, and illustrate a diverse assemblage of plants, bivalves, snails, crustaceans, insects, rays, bony fish, salamanders, turtles, lizards, snakes, crocodilians, birds, and mammals.^[3]^[4]^[5]^[6]^[7]^[8]

References

^ ^a ^b Conrad, J. L. (2006). "An Eocene shinisaurid (Reptilia, Squamata) from Wyoming, U.S.A.". Journal of Vertebrate Paleontology. 26 (1): 113–126. doi:10.1671/0272-4634(2006)26[113:AESRSF]2.0.CO;2.
^ ^a ^b Smith, M. E.; Carroll, A. R.; Singer, B. S. (2008). "Synoptic reconstruction of a major ancient lake system: Eocene Green River Formation, western United States". Geological Society of America Bulletin. 120 (1–2): 54–84. Bibcode:2008GSAB..120...54S. doi:10.1130/B26073.1.
^ Oriel, S. S.; Tracey J. I., Jr. (1970). Uppermost Cretaceous and Tertiary stratigraphy of Fossil Basin, southwestern Wyoming (PDF). Reston, VA: U.S. Geological Survey. Professional Paper 635.
^ McGrew, P. O.; Casilliano, M. (1975). "The geological history of Fossil Butte National Monument and Fossil Basin". National Park Service Occasional Paper. 3.
^ Grande, L. (1984). Paleontology of the Green River Formation, with a review of the fish fauna. Bulletin 63 (2nd ed.). Laramie, WY: Geological Survey of Wyoming.
^ Breithaupt, B. H. (1990). "Early Tertiary fossils and environments of Wyoming: Jackson to Fossil Butte National Monument". In Roberts, S. (ed.). Geologic field tours of western Wyoming and parts of adjacent Idaho, Montana, and Utah. Public Information Circular 29. Laramie, WY: Geological Survey of Wyoming. pp. 57–72.
^ Grande, L.; Buchheim, H. P. (1994). "Paleontological and sedimentological variation in early Eocene Fossil Lake". Contributions to Geology. 30 (1): 33–56. Bibcode:1994RMGeo..30...33G. doi:10.2113/gsrocky.30.1.33.
^ Buchheim, H. P.; Eugster, H. P. (1998). "Eocene Fossil Lake: the Green River Formation of Fossil Basin, southwestern Wyoming". In Pitman, J. K.; Carroll, A. R. (eds.). Modern & ancient lake systems: new problems and perspectives. Publication 26. Salt Lake City, UT: Utah Geological Association. pp. 191–208.