Trinacromerum

  (Redirected from Trinacromerum bentonianum)

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
Trinacromerum ROM Dec29 07.png
A cast specimen of Trinacromerum kirki at the Royal Ontario Museum
Scientific classification e
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

DescriptionEdit

 
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".

ClassificationEdit

 
Profile view of a cast of a Manitoban specimen of Trinacromerum kirki
 
Trinacromerum bentonianum from the Late Cretaceous of Kansas

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

Plesiosauroidea 

Cryptoclididae

 Leptocleidia 

Leptocleididae

 Polycotylidae 

Edgarosaurus

Plesiopleurodon

QM F18041

Eopolycotylus

Polycotylus

Thililua

Trinacromerum

Manemergus

Dolichorhynchops herschelensis

Dolichorhynchops

Palmulasaurus

See alsoEdit

ReferencesEdit

  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 and 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. doi:10.1111/j.1475-4983.2011.01083.x.CS1 maint: uses authors parameter (link)

External linksEdit