Media Releases

Ancient meat-loving predators survived for 35 million years

December 6, 2011

TORONTO, ON — A species of ancient preda­tor with saw-like teeth, sleek bod­ies and a vora­cious appetite for meat sur­vived a major extinc­tion at a time when the dis­tant rel­a­tives of mam­mals ruled the earth.

A detailed descrip­tion of a fos­sil that sci­en­tists iden­ti­fy as a vara­nopid “pely­cosaur” is pub­lished in the Decem­ber issue of Natur­wis­senschaften – The Sci­ence of Nature. Pro­fes­sors Sean Modesto from Cape Bre­ton Uni­ver­si­ty, and Robert Reisz from Uni­ver­si­ty of Toron­to Mis­sis­sauga pro­vide evi­dence that a group of ancient, agile preda­tors called vara­nopids sur­vived for more than 35 mil­lion years, and co-exist­ed with more advanced ani­mals.

Modesto and the team per­formed a detailed exam­i­na­tion of the par­tial skull and jaw of the youngest known prim­i­tive mam­mal-like ani­mal, which they believe lived over 260 mil­lion years ago in the Per­mi­an Peri­od. The fos­sils are from rocks form­ing the Pris­terog­nathus Assem­blage Zone of the Beau­fort Group in South Africa.

“These ani­mals were the most agile preda­tors of their time, sleek-look­ing when com­pared to their con­tem­po­raries,” says Reisz. “They seem to have sur­vived a major change in the ter­res­tri­al fau­na that occurred dur­ing the Mid­dle Per­mi­an, a poor­ly under­stood extinc­tion event in the his­to­ry of life on land.”

Accord­ing to Modesto, who was once a stu­dent at U of T Mis­sis­sauga, “these ancient ani­mals real­ly looked like mod­ern goan­nas or mon­i­tor lizards, but are actu­al­ly more close­ly relat­ed to mam­mals.”

The fos­sil revealed teeth that are strong­ly flat­tened, curved towards the throat and with fine­ly ser­rat­ed cut­ting edges typ­i­cal of hypercarnivores–animals with a diet that con­sists of more than 70 per cent meat.

Modesto and his col­leagues con­clud­ed that these vara­nopids had a longer co-exis­tence with ani­mals that even­tu­al­ly evolved into mam­mals than pre­vi­ous­ly believed. They sug­gest that the den­tal and skele­tal design of vara­nopids, rem­i­nis­cent of the Komo­do drag­on of today, may have con­tributed to their long sur­vival and their suc­cess.

For more infor­ma­tion, please con­tact:

Robert R. Reisz
Depart­ment of Biol­o­gy
Uni­ver­si­ty of Toron­to Mis­sis­sauga
905–828-5364/3982
robert.reisz@utoronto.ca

Sean Modesto
Depart­ment of Biol­o­gy
Cape Bre­ton Uni­ver­si­ty
902–563-1972
sean_modesto@cbu.ca

Nicolle Wahl
Uni­ver­si­ty of Toron­to Mis­sis­sauga
905–569-4656
nicolle.wahl@utoronto.ca