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Machimosaurus rex, new species is largest and youngest (Lower Cretaceous) teleosaurid found

Ben Creisler

A new paper:

Federico Fanti, Tetsuto Miyashita, Luigi Cantelli, Fawsi Mnasri, Jihed
Dridi, Michela Contessi & Andrea Cau (2016)
The largest thalattosuchian (Crocodylomorpha) supports teleosaurid
survival across the Jurassic-Cretaceous boundary.
Cretaceous Research (advance online publication)


Machimosaurus rex is a new teleosaurid crocodylomorph from Tunisia.
It is the largest known thalattosuchian, up to 10 m in length.
M. rex, the first Cretaceous teleosauroid found, was the
last-surviving of its group.


A new teleosaurid from the Lower Cretaceous of Tataouine (Tunisia),
Machimosaurus rex sp. nov., definitively falsifies that these
crocodylomorphs faced extinction at the end of the Jurassic.
Phylogenetic analysis supports its placement closer to M. hugii and M.
mosae than M. buffetauti. With the skull length up to 160 cm and an
estimated body length of 10 m, M. rex results the largest known
thalattosuchian, and the largest known crocodylomorph at its time.
This giant thallatosuchian probably was an ambush predator in the
lagoonal environments that characterized the Tethyan margin of Africa
during the earliest Cretaceous. Whether the Jurassic-Cretaceous mass
extinction was real or artefact is debated. The discovery of M. rex
supports that the end-Jurassic crisis affected primarily Laurasian
biota and its purported magnitude is most likely biased by the
incomplete Gondwanan fossil record. The faunal turnovers during the
J-K transition are likely interpreted as local extinction events,
triggered by regional ecological factors, and survival of
widely-distributed and eurytypic forms by means of habitat tracking.