'Baby' shark the only one of its kind

american pocket shark
The American pocket shark. Photo credit: Tulane University/Mark Doosey

It's tiny, but no baby.

A unique shark so small you could fit a fully-grown adult in the palm of your hand has finally been given a name.  

The 14cm-long American pocket shark, as its been dubbed, was found in the Gulf of Mexico 2010. 

Looking somewhat like a sperm whale, it's only the second-ever pocket shark ever found - but it's so different to one found in the eastern Pacific Ocean, it's been determined as an all new species. 

"In the history of fisheries science, only two pocket sharks have ever been captured or reported," said Mark Grace, one of the scientists who examined the specimen. "Both are separate species, each from separate oceans. Both are exceedingly rare."

Don't let the name fool you - they're not called pocket sharks because of their size, even though they definitely could fit in your pocket. The name refers to pocket-type glands found near their pectoral fins. 

"The fact that only one pocket shark has ever been reported from the Gulf of Mexico, and that it is a new species, underscores how little we know about the Gulf," said Henry Bart, director of the Tulane Biodiversity Research Institute, who contributed to the study.

Details of the find were published in journal Zootaxa