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.[1]

Trinacromerum
Temporal range: Late Cretaceous
Mounted T. kirki cast at the Royal Ontario Museum
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Sauropterygia
Order: Plesiosauria
Family: Polycotylidae
Genus: Trinacromerum
Cragin, 1888
Species
  • T. bentonianum Cragin, 1888 (type)
  • T. kirki Russell, 1935

Description

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Trinacromerum with a human to scale

Trinacromerum was 3 meters (9.8 feet) long. Its teeth show that it fed on small fish.[1]

The long flippers of Trinacromerum enabled it to achieve high swimming speeds.[1] Its physical appearance was described by Richard Ellis as akin to a "four-flippered penguin."[2] Its name means "three tipped femur".

Classification

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T. bentonianum life restoration

Below is a cladogram of polycotylid relationships from Ketchum & Benson, 2011.[3]

Plesiosauroidea 

See also

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References

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  1. ^ a b c Ellis, Richard (2003). Sea Dragons: Predators of the Prehistoric Oceans. University Press of Kansas. p. 189. ISBN 0-7006-1269-6.
  2. ^ Ellis, 190
  3. ^ Hilary F. Ketchum; Roger B. J. Benson (2011). "A new pliosaurid (Sauropterygia, Plesiosauria) from the Oxford Clay Formation (Middle Jurassic, Callovian) of England: evidence for a gracile, longirostrine grade of Early-Middle Jurassic pliosaurids". Special Papers in Palaeontology. 86: 109–129.
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