A little Linguipolygnathus

Variants of Linguipolygnathus linguiformis over time, from Bardashev et al. (2002).

Three points for this ID challenge go to Adam Yates who recognised the objects in the figure as P-elements of an ozarkodinid conodont (the first person to identify them as a conodont looses out on points because they didn't supply any supporting comments). Linguipolygnathus linguiformis is the type species of Linguipolygnathus, one of the genera carved by Bardashev et al. (2002) out of the large older genus Polygnathus. I've commented on the taxonomic insanity of Bardashev et al. in a previous post, though the idea of subdividing Polygnathus is not in itself a bad one (and note that if Linguipolygnathus were synonymised with its supposed polyphyletically-ancestral genus Eolinguipolygnathus we'd be left with a single monophyletic genus).

Many discussions of conodonts make reference to their minuteness (I've done it myself in the past) and the preserved conodont fossils are certainly minute. However, I must confess to only realising fairly recently that, just because the preserved fossils are minute, doesn't necessarily mean that the (largely soft-bodied and hence rarely preserved) animals themselves were. Of the two best-preserved body fossils of conodonts available to us, the remains of Promissum are those of an animal about 20 cm long. Even the more modestly sized Clydagnathus, which is apparently more like the usual run of conodonts, would have been about 6 cm long in life: not huge, but still comparable in size to a modern anchovy.

REFERENCES

Bardashev, I. A., K. Weddige & W. Ziegler. 2002. The phylomorphogenesis of some Early Devonian platform conodonts. Senckenbergiana Lethaea 82 (2): 375-451.