Complete Pregnant Ichthyosaur Among Incredibly Well-Preserved Fossils Revealed By Retreating Glacier


Rachael Funnell

Digital Content Producer

clockMay 12 2022, 17:23 UTC
pregnant ichthyosaur retreating glacier

The incredible fossil finds were revealed by a retreating glacier. Images courtesy of The University of Manchester

Ancient treasures came spilling out of a glacier in Patagonia during March and April of this year including Chile’s first complete ichthyosaur specimen. Named “Fiona”, she sits among a clutch of 23 prehistoric reptiles recovered in the region and comes complete with several embryos.

The fossilized remains are estimated to be between 129 and 139 million years old from the Early Cretaceous and were recovered from melting ice in the Tyndall Glacier area of Chilean Patagonia by an expedition led by The University of Magallanes (UMAG). Sat inside the Torres del Paine National Park, the remains were able to be carefully packed and carried out via helicopter.


"The results of the expedition met all expectations, and even more than expected," said Dr Judith Pardo-Pérez, the first female paleontologist to lead an expedition of this magnitude in Patagonia, in a statement.

A good thing too, since it was a grueling 31-day-mission to find, extract, and carefully wrap the astonishing and fragile fossil remains. The retreating glacier rewarded their efforts with Fiona, the only known-to-science specimen of a pregnant female ichthyosaur from the Valanginian-Hauterivian age.

Dr Judith Pardo-Pérez examining the "best-preserved skull of an ichthyosaur" found at Tyndall by Dr Dean Lomax. Images courtesy of The University of Manchester

The first-of-its-kind fossil was excavated by a team led by paleontological excavator Héctor Ortiz from the Chilean Antarctic Institute and the University of Chile and paleontological technician Jonatan Kaluza from Fundación de Historia Natural Félix de Azara and CONICET.

“At 4 metres [13 feet] long, complete, and with embryos in gestation, the excavation will help to provide information on its species, on the palaeobiology of embryonic development, and on a disease that affected it during its lifetime," Pardo-Pérez continued.


Fiona, alongside her 23 ichthyosaur specimen pals, marks the finest early Cretaceous ichthyosaur deposit in the world, says the scientist, being such an impressive collection of incredibly well-preserved fossilized remains. The extracted specimens will now contribute to research into these ancient animals, their characteristics, and how they lived.

“We hope to obtain results on the diversity, disparity and palaeobiology of the ichthyosaurs of the Tyndall Glacier locality, establish degrees of bone maturity and ecological niches to evaluate possible dietary transitions that occurred throughout their evolution and that could help to establish palaeobiogeographical connections with ichthyosaurs from other latitudes,” Pardo-Pérez said.

Héctor Ortiz, Jonatan Kaluza, and Dean Lomax overseeing the excavation. Images courtesy of The University of Manchester

Dr Dean Lomax – who readers may remember from the Rutland ichthyosaur which he hailed "one of the greatest finds in British palaeontological history" – was also along for the ride as a fellow paleontologist and "Visiting Scientist" affiliated with The University of Manchester. Forming part of the collaborative team behind the string of discoveries, he himself uncovered a few of the treasures including a juvenile ichthyosaur’s skull which is thought to be the best-preserved specimen of its kind found to date.

“The considerable number of ichthyosaurs found in the area, including complete skeletons of adults, juveniles, and newborns provides a unique window into the past,” he said. “The international collaboration helps to share this exceptional ichthyosaur graveyard with the world and, to a large extent, to promote science.”


[H/T: Vice]

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