Monday, August 30, 2010

A Mantellisaurus Rampant, or Coo-Coo for Kukufeldia

On Thursday of last week, I wrote about the coat of arms for Maidstone, the small town in Kent where a quarry owned by W.H Bensted yielded important Iguanodon bones in 1834.

The Maidstone Slab. From wikimedia commons.

In the comments, Matt Martyniuk questioned whether those bones would still be considered Iguanodon. It was a good question, because Iguanodon happens to be one of those genera that is a taxonomic cluster... well, you know what I'm getting at. Check out the Iguanodon page at Wikipedia for a daunting list of putative Iguanodon species later reassigned to other genera and others currently considered dubious.

A paper published in the latest Zootaxa is another attempt at resolving the mess, reaching far back to teeth described by the father of Iguanodon, Gideon Algernon Mantell, in 1848. Andrew McDonald of the University of Pennsylvania with Paul Barrett and Sandra Chapman from the Natural History Museum in London have erected a new genus, Kukufeldia tilgatensis, after analyzing a collection of teeth assigned to Iguanodon by Mantell in 1848. The authors justify the new genera on the grounds that the teeth are sufficiently different from any other Iguanodon teeth (incidentally, Mantell never assigned his teeth to a species, only working on the level of the genus - that was how he rolled).

This naturally leads to the question: With the genus such a mess, what's the basis for comparison? Well, we're really lucky to have the three dozen Iguanodons discovered at the mine at Bernissart, Belgium in 1878; the skeletons provide a solid mark by which to measure other Iguanodons. Because of the quality of these specimens, Iguanodon bernissartensis was named the type species for the genus in 2000.

The teeth studied by McDonald et al originated from the same geological formation as the original teeth discovered by Mantell, and it's possible that those belonged to their Kukufeldia as well. There's so little to go on, they may never be positively tied to a valid species. However, Kukufeldia may be disputed in the near future. It comes from a geological formation called the Wealden supergroup, which was the subject of a recent overview by veteran Iguanodon researcher David Norman, also published in Zootaxa. Norman maintains that there are only two iguanodontians that can be named with any certainty from the Wealden's Upper Cretaceous deposits: Iguanodon bernissartensis and Mantellisaurus atherfieldensis, which was named by Greg Paul a few years ago. At the end of the abstract, Norman promises more work to come on providing further clarity to the genus.

So, you see why I called Matt a "sick, sick man" in response to his comment. Taxonomy would be a good candidate for an episode of "Dirty Jobs." I bet it would break Mike Rowe's spirit.

What of the Maidstone coat of arms? It's up in the air, but I'll hazard a guess. In the early nineties, David Norman reevaluated the Maidstone slab and noted that the dinosaur it most resembled was Iguanodon atherfieldensis (see page 234 of this volume). That species was the one which Greg Paul renamed Mantellisaurus atherfieldensis. As Norman supports Mantellisaurus in his latest writings, this looks to be a decent candidate for Maidstone's patron dinosaur. To revise the title of my original Maidstone post, the coat of arms features a Mantellisaurus rampant. I'm sure the fair citizens of Maidstone would find that most agreeable.

UPDATE: Check out Darren Naish's three-part series on Iguanodon at the SciAm Guest Blog. Part one is here.

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