Biology

‘Blood biting tyrant swimmer’ discovered

Blood biting tyrant swimmer

Tyrannoneustus lythrodectikos. Illustration credit: Dmitry Bogdanov/University of Edi/PA

Bones of a super predator from the Jurassic period have been identified as a new species by researchers at the University of Edinburgh.

The new species has been named Tyrannoneustes lythrodectikos, which means ‘blood-biting tyrant swimmer’ in Ancient Greek. It has been classified in a family of fully aquatic crocodyliforms, which are related to modern day crocodiles.

The species has helped researchers form a picture of how this family was evolving about 165 million years ago, providing a missing link between marine crocodiles that fed on small prey, and predators higher in the food chain that fed on larger prey (like modern day killer whales).

The partial skeleton is currently the only specimen of this species, which contains remains of its jawbone and teeth. The skeleton was found in one of the numerous clay pits owned by Alfred Leeds in the early 20th century.  Leeds donated numerous fossil specimens from his private collection to public institutions during his lifetime, but as the Tyrannoneustes lythrodectikos was incomplete, with very little preservation of skull and none of the forelimbs, this specimen remained in his private collection until 1919 (two years after his death).

There was very little interest in this fossil specimen until 2011 when Dr Mark Young, from the University of Edinburgh, found it at Glasgow’s Hunterian museum.

Dr Young told the Student that although the species is theorised to have fed on quite large prey compared with some of the other known crocodyliforms, it was not safe from the larger carnivores in the ocean, “Tyrannoneustes could have been predated upon by the giant pliosaurs of the Oxford Clay Formation (such as Liopleurodon). Other marine crocodile fossils show bite marks, some of which show evidence of healing (meaning the croc survived the attack).”

The state of the fossil has led to some restrictions on his research, however, “Unfortunately, nothing can be said about how and what Tyrannoneustes fed on. We have no preserved stomach contents.

“From the species mandibular and dental morphologies we can infer it could swallow smaller prey, and/or was capable of biting into and breaking larger prey into pieces small enough to swallow. These morphologies include: enlarged teeth, the teeth have serrated edges, a characteristic shape change of the mandible allowing it to open its mouth wider (increased gape), and a unique arrangement of the upper and lower tooth rows which would have facilitated shearing during a bite (increased the ease at which it could break large prey into smaller pieces).”

Originally published in the Student, February 2013.

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