Metoposaurus: Prehisroric Animal of the Week

This week is yet another newly described species!  Say hello to Metoposaurus algarvensis!  Metoposaurus was a huge amphibian that lived in what is now Portugal, during the Triassic Period, about 230 million years ago.  This slimy beast was large, having been able to grow to ten feet long from snout to tail.  Like all known amphibians (at least as adults), Metoposaurus was probably a predator, snapping up any animal it could fit into its massive jaws, which were lined with many small, pointed teeth.  The name, Metoposaurus, translates to "front lizard" in reference to its gigantic head, which was flat, and made up almost a third of its body length.  Despite the second part of the genus name, this creature was not a lizard (which is a reptile) but more closely related to modern frogs and salamanders.

Metoposaurus algarvensis life reconstruction by Christopher DiPiazza.

 Metoposaurus was part of an ancient lineage, called the temnospondyls.  Temnosondyl amphibians are extinct now, but were EXTREMELY successful well into the Mesozoic Era.  The more famous, Eryops, was another example of a temnospondyl.  The species we are covering today (because there are more than one known species of Metoposaurus) is known from multiple specimens that were unearthed in very close proximity to one another at the bottom of what was once a body of water.  It is hypothesized that these creatures met their deaths when their watery habitat shrunk to the point of eventually drying out, which caused them to huddle together to where the moisture was in their last hours of life.  All amphibians need water in order to survive.  Depending on the species, they cant survive without exposure to it for prolonged periods of time.

Two Metoposaurus algarvensis skulls.

When alive, Metoposaurus would have been one of the largest animals in its habitat.  It likely was an ambush predator, since its limbs were proportionally short and not very powerful.  Some scientists believe Metoposaurus was semi aquatic, having rested at the bottom of a body of fresh water, using its flattened head and body to hide from passing prey, sucking them into its huge jaws when they swam too close.  Other scientists believe Metoposaurus was capable of burrowing under loose earth, which is something common amongst modern salamanders, some of which look similar to this prehistoric beast.  Although no actual dinosaur remains have been found from the site Metoposaurus algarvensis is from (which still has many undiscovered fossils hidden within it), it is likely that there were early ones alive back then that even may have fallen prey to this mighty amphibian in its day. 

That is all for this week!  Special thanks to paleontologist, and friend of the site, Steve Brusatte, who helped discover and describe this creature, for lending his expertise to me when writing this post.  As always feel free to comment below or on our facebook page!

References

Brusatte, S., Butler, R., Mateus, O., Steyer, S. 2015. A new species of Metoposaurus from the Late Triassic of Portugal and comments on the systematics and biogeography of metoposaurid temnospondyls. Journal of Vertebrate Paleontology. doi: 10.1080/2724634.2014.912988

Steyer, J. S., Mateus O., Butler R. J., Brusatte S. L., & Whiteside J. H. (2011) "A new metoposaurid (temnospondyl) bonebed from the Late Triassic of Portugal", Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology, 200.

T. Sulej, "Species discrimination of the Late Triassic temnospondyl amphibian Metoposaurus diagnosticus", Acta Paleontologica Polonica, 47, 535-546 (2002)