Monday, January 26, 2009

Worst case of mistaken identity since Aachenosaurus!


OK on with Fish fortnight,
Aachenosaurus is an infamous a case of misidentification where some pieces of petrified wood were mistaken for dinosaur bones, and a name was coined for them in the literature. The small pieces of bone in the photos above were also strikingly misidentified in the BPI catalogue as belonging to a dinosaur (though fortunately never published as such). They actually belong to a fish, a ray-finned fish (actinopterygian) to be a little more precise. As fish they are very interesting because the come from the upper Elliot Formation, and as far as I can tell are the first recognized ray-finned fish from this unit (lungfish are known from the odd small toothplate here and there). The upper Elliot Formation was deposited in arid conditions with most of the streams being small and ephemeral. Nonetheless ray-fins can’t cocoon themselves when their pond dries up the way some lungfish can and their presence indicates that some permanent water bodies, however small, existed on the upper Elliot floodplain. That’s all I can say about this fish right now - the fossil will be subjected to further prep and study.

7 comments:

Anonymous said...

Talk about mistaken identity. That happened to the Dromaeosaurs after the First Jurassic Park was released.

Christopher Taylor said...

I have a paper sitting at home whose title says it all - "Trigonocarpus excrescens Janssen, 1940, a supposed seed from the Pennsylvanian of Illinois, is a milliped".

Anonymous said...

Here`s another one:
Schweigert, G. and Etter, W. (2008): On the true nature of the supposed urodelan amphibian Boomgaardia v. Huene, 1948 from the Middle Jurassic of SW Germany - a tanaidacean! Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 248: 123-127

If you don't know what tanaidaceans are, they're crustaceans. It was a completely preserved specimen.

Anonymous said...

The one on the right is part of Mick Jagger, I believe.

Anonymous said...

These are bits of a semionotid, probabaly Semionotus. Above left are some scales and bits I can't recognize; lower left is a parasphenoid, anterior to right, posterior bits broken off; lower right is an upside down cleithrum, in present coordinates, anterior is to right.

Unknown said...

It looks like an obvious ray finned cleithrum to me...

Unknown said...

Yep,..I see Olsen is seeing the same as I with the parasphenoid going left to right with the caudal end at the left and the right side being the rostral end right where one usually finds the vomer in ray-finned fish (at least how it would be seen in neopterygians),,,