Chunerpeton: Prehistoric Animal of the Week

This week we honor a prehistoric amphibian that has ties to animals that are near and dear to my heart today.  Check out Chunerpeton tianyensis!  Chunerpeton is one of the first known salamanders to ever appear in the fossil record.  It lived during the Jurassic Period, about 160 million years ago, in what is now China.  It measured about seven inches long on average, and like its living relatives, would have been a predator, capturing and swallowing whole any small animal it could fit in its mouth.  The genus name, Chunerpeton, translates to "Early Creeper".  When alive, Chunerpeton would have lived nearby some dinosaurs like Anchiornis and Eosinopteryx.

Life reconstruction of Chunerpeton tianyensis by Christopher DiPiazza. I opted for no gills since all its living relatives don't have them as fully grown adults.

Chunerpeton is known from hundreds of well preserved fossils.  During the Jurassic, the lake in which these Chunerpeton lived was buried under a layer of ash when a nearby volcano erupted, preserving them all to eventually become wonderfully preserved fossils.  Many specimens retain skin, eyes, stomach contents (included small shrimp in case you were wondering) and external gills.  The fact that Chunerpeton is known from all the way back during the Jurassic is amazing.  Before its discovery only a few years ago, the oldest known salamander fossils were from only about 65 million years ago, not long after the great Mesozoic extinction that wiped out most of the dinosaurs.  Of course other kinds of amphibians have been around since MUCH earlier, but Chunerpeton was the first occurrence of a true salamander like we see around us today. 

Chunerpeton fossil.  You can see where external gills would have been just behind the skull.

What kind of salamander was Chunerpeton though?  Scientists identified it as a member of the salamander family, cryptobranchidae.  Modern examples of cryptobranchids are the largest living amphibians, like the Chinese Giant Salamander. (Andrias davidianus)  The highly endangered Hellbender (Cryptobranchus alleganiensis) from North Eastern United States is also a cryptobranchid.  Chunerpeton is also closely related to another family of modern salamander, called hynobidae.  Both hynobids and cryptobranchids spend most of their time in cool, clean water, and are voracious predators, snapping up any kind of prey that wanders too close to their mouths.  Like most amphibians, they start out as a fully aquatic larval form with gills.  As they age they lose the gills and gain the ability to breathe air but still prefer to spend most of their time in the water.  It is likely Chunerpeton was the same way.  Many Chunerpeton fossils, like I stated earlier, preserved external gills.  This leaves many to believe that Chunerpeton retained its gills into adulthood, which is exhibited in some kinds of modern salamanders.  These fossils could also just be of juveniles, however.

My pet Hynobius dunni begging for food at the front of the tank.

 Like I shared a few days ago, I personally keep many salamanders in my home as pets.  Amongst them I do have one kind, a hynobid, that is closely related to the ancient Chunerpeton.  It is called a Japanese Oita Salamander. (Hynobius dunni)  Quite a little cutie!  He eats worms and crickets right from my fingers too!

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

References

Ke-Qin Gao & Neil H. Shubin (27 March 2003). "Earliest known crown-group salamanders". Nature 422 (6930): 424–428. doi:10.1038/nature01491.

Roach, John. "China Ash Yields Salamander Evolution Secrets." National Geographic. National Geographic Society, 28 Oct. 2010. Web.

Steyer, Sebastien. Earth before the Dinosaurs. Bloomington: Indiana UP, 2012. Print.