Genus
Valid Extinct

Trinacromerum

Cragin 1888

Trinacromerum is an extinct genus of sauropterygian reptile, a member of the polycotylid plesiosaurs. It contains two species, T. bentonianum and T. kirki. Specimens have been discovered in the Late Cretaceous fossil deposits of what is now modern Kansas and Manitoba. Some fossils are also found in the Southern United States such as in the Mooreville Chalk of Alabama.

Temporal range
Triassic
Jurassic
Cretaceous
Paleogene
Neogene
252 201 145 66 0 Ma
PBDB occurrences
18
Group
Sauroptérygiens
Carnivore aquatic, depth=surface Marine
Trinacromerum
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Royal Ontario Museum, Toronto, Canada, 2022 © Thomas Quine · CC BY 2.0 · Wikimedia
Trinacromerum
Trinacromerum
PBDB ↗ Wikipedia ↗
Classification
Sauropterygia Suborder
›
Plesiosauria Order
›
Plesiosauroidea Superfamily
›
Polycotylidae Family
›
Polycotylinae Subfamily
›
Trinacromerum Genus
Measurements
Length
3 m ⓘ
Fossil sites 18 geolocated sites
Distribution
Top countries
🇺🇸 United States
15
🇨🇦 Canada
3
Geological formations
Carlile Shale
5
Greenhorn Limestone
4
Pierre Shale
2
Mowry Shale
1
Tropic Shale
1
Lake Waco
1
Favel
1
Temporal distribution
Campanian (83.6–72.2 Ma)
2
Turonian (93.9–89.8 Ma)
11
Cenomanian (100.5–93.9 Ma)
4
Albian (113.2–100.5 Ma)
1
Species (5)
Ceraunosaurus brownorum subjective synonym of Trinacromerum bentonianum 101 Ma
Trinacromerum anonymum subjective synonym of Trinacromerum bentonianum 101 Ma
Trinacromerum bentonianum 101 Ma
Trinacromerum kirki 94 Ma
Trinacromerum willistoni subjective synonym of Trinacromerum bentonianum 101 Ma
Images 2
Bibliography
Original description
J. J., Jr. Sepkoski. 2002. A compendium of fossil marine animal genera. Bulletins of American Paleontology 363:1-560
Bibliography (8)
L. B. Albright, D. D. Gillette, and A. L. Titus. 2007. Plesiosaurs from the Upper Cretaceous (Cenomanian-Turonian) Tropic Shale of southern Utah, part 2: Polycotylidae. Journal of Vertebrate Paleontology 27(1):41-58 DOI ↗
B. A. Schumacher and M. J. Everhart. 2005. A stratigraphic and taxonomic review of plesiosaurs from the old "Fort Benton Group" of central Kansas: a new assessment of old records. Paludicola 5(2):33-54
D. Bardack. 1968. Fossil vertebrates from the marine Cretaceous of Manitoba. Canadian Journal of Earth Sciences 5:145-153 DOI ↗
J. T. Thurmond. 1968. A new polycotylid plesiosaur from the Lake Waco Formation (Cenomanian) of Texas. Journal of Paleontology 42(5):1289-1296
J. H. Ostrom. 1965. Cretaceous vertebrate faunas of Wyoming. Wyoming Geological Association Guidebook 19:35-41
E. S. Riggs. 1944. A new polycotylid plesiosaur. The University of Kansas Science Bulletin 30(8):77-87 DOI ↗
L. S. Russell. 1935. A plesiosaur from the Upper Cretaceous of Manitoba. Journal of Paleontology 9(5):385-389
S. W. Williston. 1908. North American plesiosaurs Trinacromerum. Journal of Geology 16(8):715-736 DOI ↗