Fossils of huge ancient lizard with spiky armor skin recovered in Australia

Skink with thick armor skin

The supersized skink was the size of an adult human arm and scared the predator away with its thick armor scales covering its skin. Its fossilized bones were recovered from Wellington Caves in New South Wales, Australia. 

“In the dig at Wellington Caves, we started finding these spiked armored plates that had surprisingly never been recorded before. We knew we had something interesting and unique,” said Diana Fusco, co-author of the study, from the Flinders University Palaeontology Laboratory, in an official statement. 

According to fossil evidence, Frangens was at least 1,000 times larger than the typical Australian garden skink (Lampropholis guichenoti), which weighs only 2g.  

The authors emphasize that due to its size, it was most likely a sluggish-moving beast. 

Lived alongside other megafauna

The fossils show that even little reptiles were rather large during the Pleistocene era. Diverse megafauna dominated parts of the world during the Pleistocene era. 

This strange species most likely coexisted with prehistoric mammals such as marsupial lions, diprotodons, and short-faced kangaroos around 50,000 years ago. 

The extinction of Frangens correlates with the loss of the majority of megafauna during this time period. It also shows that end-Pleistocene extinctions were more severe, affecting not just bigger species but also comparatively small organisms like skink. 

“Deciphering how Pleistocene animals adapted, migrated, or what eventually caused their extinctions might help us conserve today’s fauna, which faces pressures such as changing climate and habitat destruction,” concluded lead author Dr. Kailah Thorn, from the Western Australian Museum, who studied the fossils as part of her Ph.D. at Flinders University.

The study is published in the journal Proceedings of the Royal Society of London B: Biological Sciences.

Study abstract:

There are more species of lizards and snakes (squamates) alive today than any other order of land vertebrates, yet their fossil record has been poorly documented compared with other groups. Here, we describe a gigantic Pleistocene skink from Australia based on extensive material that includes much of the skull and postcranial skeleton, and spans ontogenetic stages from neonate to adult. Tiliqua frangens substantially expands the known ecomorphological diversity of squamates. At approximately 2.4 kg, it was more than double the mass of any living skink, with an exceptionally broad, deep skull, squat limbs and heavy, ornamented body armour. It probably filled the armoured herbivore niche that land tortoises (testudinids), absent from Australia, occupy on other continents. Tiliqua frangens and other giant Plio-Pleistocene skinks suggest that small-bodied groups that dominate vertebrate biodiversity might have lost their largest and often most morphologically extreme representatives in the Late Pleistocene, expanding the scope of these extinctions.