Monday, January 22, 2018

Laganosuchus: Beast of the Week

Today we will be checking out a wonderfully specialized prehistoric crocodile.  Check out Lagaosuchus thaumastos!

Laganosuchus lived in what is now Niger, Africa, during the Cretaceous period, about 95 million years ago.  According to the known fossil material, adults could grow to be over twenty feet long from snout to tail.  Like most crocodiles, Laganosuchus would have been a meat-eater when alive.  The genus name, Laganosuchus, translates to "Pancake Crocodile" because of the shape of its snout.  When alive, Laganosuchus would have shared its habitat with fellow crocodilian, Kaprosuchus, and the plant-eating dinosaur, Nigersaurus.

My Laganosuchus life reconstruction in watercolors.  This poor fellow was part of a larger prey for a Spinosaurus.

Laganosuchus didn't earn the name, "Pancake Crocodile", for nothing.  This crocodile's jaws were extremely wide and shallow, causing it to have an extremely flat head.  The jaws were lined with small, pointed teeth.  This suggest that Laganosuchus was adapted to hunting fish in a specialized manner.  The leading hypothesis as to exactly how Laganosuchus did this is that it would lie still in the water for extended periods of time with its mouth ajar, becoming part of the environment for passing fish.  As fish became more and more comfortable around it, they would be more comfortable swimming closer and closer to the mouth.  Some may have even swam inside the mouth, seeking refuge in the seemingly cave-like structure.  When this happened, Laganosuchus could shut its jaws lightning-fast, catching and eating any fish unfortunate enough to be too close at the time.  Laganosuchus and its proposed hunting style always reminded me of this scene from the Jim Henson movie, The Dark Crystal.  Watch at twenty five seconds in if you want to see what I mean.

Unlike many other species of crocodilian, who's jaws are strong and good at holding tight under pressure, the jaws of Laganosuchus are rather thin and delicate.  This further supports the idea that this crocodile wasn't hunting large prey, rather focusing on smaller fish and other animals instead.  It's contemporary and neighbor, Kaprosuchus, may have filled that niche of going after larger prey with its shorter, but more powerful jaws and proportionally larger teeth.

Lower jaw of Laganosuchus featured in Paul Sereno's 2009 paper.  Note how thin it is and how proportionally small the tooth sockets are.  This crocodile was probably specialized in hunting smaller fish.

Laganosuchus is an important find because it helps break the false idea that crocodilians remained completely unchanged through the Mesozoic to today.  Yes, they have been around since then, but they were far from stagnant in their evolution.  Crocodilians experimented with many different forms during their history on earth, and as is the case with Laganosuchus, some were extremely specialized.

That is all for this week!  As always feel free to comment below or on the facebook page.


 Sereno, P. C.; Larsson, H. C. E. (2009). "Cretaceous crocodyliforms from the Sahara". ZooKeys. 28 (19 November 2009): 1–143.

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