Wow! Check out this
blog post at
Amphidrome on an amazing (I think) extant
gammaroid crustacean from Siberia. I will be damned if the anterior portion of the carapace on
Acanthogammarus is not a dead ringer for the cervical armor of the Triassic aetosaur
Desmatosuchus spurensis (see Parker, 2008)! Especially check out the last
photo on the post (and reproduced below) and compare to the postcard photo of the Petrified Forest mount. Note that the proposed purpose for these structures in the crustacean is defensive, whereas I have argued recently that such spines in aetosaurs may also be used for species recognition and display
(Parker, 2007).
Very cool crustacean. Where can I get one? ;)
top photo is from here.
REFERENCES
Parker, W.G. 2007. Reassessment of the aetosaur ‘
Desmatosuchus’
chamaensis with a reanalysis of the phylogeny of the Aetosauria (Archosauria: Pseudosuchua). Journal of Systematic Palaeontology 5: 41-68. doi:10.1017/S1477201906001994
Parker, W.G. 2008. Description of new material of the aetosaur
Desmatosuchus spurensis (Archosauria: Suchia) from the Chinle Formation of Arizona and a revision of the genus
Desmatosuchus. PaleoBios 28:1–40.
Why wouldn't it be defense for the aetosaur? Ridiculously cool convergence, though!
ReplyDeleteThat's pretty remarkable. If there were definitive evidence that the spines serve a particular function in the gammaroids, would it be reasonable to infer a similar function in Desmatosuchus? Too speculative?
ReplyDeleteAt any rate, I think both of them would make awesome Kaiju.
Steve,
ReplyDeleteThat would be my guess now as well. Obviously aetosaur armor provided a degree of protection however in modern crocodiles the armor also provides support for the vertebral column during locomotion. When I reconstructed Rioarribasuchus in 2007 I determined that the spines were at the base of the tail and curved forwards, thus were of little use defensively. This suggested some other use, which I extrapolated to Desmatosuchus as well. However, if an extant organism with a similar structure uses it for defense then it would be plausible to extend this to Desmatosuchus.