Wednesday, February 9, 2011

Neptunidraco

Andrea Cau, study co-author, posing with the counter top and a reconstruction of Neptunidraco (from Nat Geo)

Meaning: "Neptune's dragon"
Species: N. ammoniticus
Nominal Author: Cau and Fanti, 2011
Age: Middle Jurassic
Location: Italy
General Description: A predatory, pelagic crocodyliform (metriorhynchid), several meters in length

You may remember my post from last May on Geosaurus in which I mentioned the "coccodrillo di Portomaggiore". At the time, Young and Andrade (2009) had proposed that the mystery croc belonged to the genus Geosaurus, but it was still awaiting a proper description. Well, the "coccodrillo di Portomaggiore" has finally been properly named and described in the March issue of Gondwana Research:

Cau, A. & F. Fanti. (2011) "The oldest known metriorhynchid crocodylian from the Middle Jurassic of North-eastern Italy, Neptunidraco ammoniticus gen. et sp. nov." Gondwana Research 19: 550-565. doi:10.1016/j.gr.2010.07.007
 
It is a very well written paper; my only criticism would be that the placement of the section on systematic paleontology and the diagnosis was a little later in the paper than I would have expected. Since this paper is the first on Neptunidraco (although there have been brief descriptions and mentions of the "coccodrillo di Portomaggiore" previously), I'm not going to do my usual "summary" of what is known about the genus, but I do highlight some interesting bits of the paper below:

Neptunidraco gen. nov. is preserved as partially disarticulated skull bones, an articulated mandible, teeth, and seven presacral vertebrae in four slabs of limestone (Rosso Ammonitico Veronese Formation), once destined to become a kitchen counter-top. Cau and Fanti also introduce a new clade name, Geosaurini nov., and define it as "the least inclusive clade containing G. giganteus, Geosaurus carpenteri, and Dakosaurus maximus." Their Strict Consensus Tree topology places Neptunidraco within Geosaurinae, just outside of Geosaurini. One thing that I found particularly interesting was Cau and Fanti's conclusion that Neptunidraco was not likely feeding on the bigger, crunchier prey of the time (ammonoids, crustaceans, armored fish, or other large marine vertebrates), but rather small, swift prey.

3 comments:

  1. Hi Susan,
    thank you very much for this post!
    As you wrote, the systematic paleontology section is placed in an unusually late position along the paper. That was a "rethorical" (in the word's original meaning) strategy. We explicitly wrote the paper in that way because we wanted to closely reflect the (chrono-)logical sequence of our research. Since the institution of the new taxon was the final among a series of logical steps in our (mine and Federico's) minds, every reader can repeat our own mental process in the paper.

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  2. Andrea,
    That's actually a really interesting way to organize a paper. I'll have to reread it with that in mind.

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  3. When I was reviewing the manuscript I found the structure quite logical. It nicely showed where in the RAV Neptunidraco was from, and that it was much older in age than previously presumed. Although, I think I suggested shortening the geological settings section!

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