Thursday, September 16, 2010

Nyctosaurus Update

Back in June, I reported on the sale of one of the famous crested Nyctosaurus specimens. A few weeks ago, Mark from a fossil selling site called DinoStar left this comment:

Not very accurate Matt. Frithiof is a very decent person who is doing a very legal business. Both KJ1 and KJ2 are still in the Brazos museum and are scheduled to be there for the next 2 years. KJ1 was sold to person who is constructing a museum. KJ2 is still for sale. Most private collections are eventually donated to a museum.

First, let me point out for the record I never said that what Frithiof and Mark do is illegal. As long as the fossils were obtained legally in the US, it's perfectly legal to sell them. That doesn't mean it isn't ethically questionable and actively detrimental to science, which I and pretty much 95% of the paleontological community would agree that it is.

Nevertheless, Mark shed some light on the nature of the infamous eBay sale. It's going to someone constructing a museum. What kind of museum or what kind of somebody remains a mystery. There are plenty of dodgy outfits out there calling themselves museums, and specimens in their collections may as well be in an 18th century cabinet of curiosity. A private "museum" is still a private collection unless the museum is somehow in the public trust, so it doesn't eliminate the hesitation most scientists would have of touching one of those specimens. But, as long as it's made freely available for study, this may be good news.

Or not, because even on Mark's own site, fossils currently on display in random small museums are being offered up for sale. For example, for only $19,000, I could become the proud owner of a Confuciusornis specimen with "scant restoration" and what looks to be an amazing anatomically incorrect ornithurine-like tail fan, straight "from China" which does not allow any exportation of fossils under any circumstances (though it does say it's from an "old collection", have the laws changed in 14 years since these birds first started turning up?). If I can buy my very own illegal Chinese pygostylian straight out of a museum's glass case, what's to keep the new owner of KJ1 from trying to cut his losses if the museum doesn't turn a profit?

KJ2, for what it's worth, is still for sale. So if you want to own a nearly one of a kind scientific treasure to hang up in your den, act soon. Maybe the Field Museum can take it off your hands in 50 years once you kick it?

Sunday, September 5, 2010

What Is A Nomen Oblitum? Not What You Probably Think

Above: Illustration of Manospondylus gigas by Matt Martyniuk, copyright.

In a previous post, I brought up the taboo subject of Manospondylus gigas, the large Lancian theropod named by E.D. Cope in 1886 and a potential senior synonym of Tyrannosaurus rex. Google "manospondylus" and the first hit is an old Q&A post by Mike Taylor called "So why hasn't Tyrannosaurus been renamed Manospondylus?"

Good question!

Aside from cultural inertia, the answer Taylor gave is this: "As of 1st January 2000, a new ICZN ruling has come into effect, saying that a name that's been considered valid for fifty years can't now be replaced by one that's been considered invalid during that time." This is also the answer Mickey Mortimer gave in some (but not all) relevant entries on the current Theropod Database. Brian Switek, in an old Laelaps post, gave the same answer: Manospondylus hasn't been considered valid in 50 years, so it's a nomen oblitum ("forgotten name"). He also suggested that this means T. rex has "protected status" which would have to be overturned by the ICZN in order for M. gigas to become valid.

The problem is that none of that has any bearing on what "nomen oblitum" actually means according to the current ICZN code. The ICZN states that in order for a name to be declared a nomen oblitum, all of the following things need to be true:
1. the senior synonym or homonym has not been used as a valid name after 1899
2. the junior synonym or homonym has been used for a particular taxon, as its presumed valid name, in at least 25 works, published by at least 10 authors in the immediately preceding 50 years
3. a paper must be published citing evidence for #2, and citing both names together, declare that the junior synonym or homonym is being made a nomen protectum ("protected name") in accordance with ICZN article 23.9.

The confusion seems to come from #2. It's not a matter of the senior name not having been used in the past 50 years, but the junior name must have been used frequently enough in recent history in order to be eligible for conservation. Clearly, T. rex meets the second criteria. But what about the first and third?

For number one, the answer is I'm not sure, but I think so. It depends on what your definition if "is" is. Has Manospondylus been used since 1899? Definitely, yes, and in several papers, as Mickey Mortimer pointed out in the comments on my previous post on this topic. But was it used as valid? Most authors, even in the early 20th century, recognized that two vertebrae were pretty poor material to be basing a species on. Many of them considered it to be what we'd now call a nomen dubium ("dubious name"). For example, here's what Matthew & Brown (1922) had to say on the subject: "Osborn has already (1917) called attention to another fragmentary type, Manospondylus gigas, as possibly identical with Tyrannosaurus but based upon an inadequate type." They don't explicitly say it's valid or invalid (I'd like to know what Osborn 1917 actually aid on the matter but don't have that paper. Anyone?).

As for number three, it appears that the situation has never been adequately addressed in the literature, so the criterion is not satisfied. The issue came up in 2000, when Peter Larson claimed to have rediscovered the original Manospondylus locality, and more of the type specimen, confirming it is the same as T. rex. As far as I know, this has never seen print beyond an AP article (Anonymous, 2000. "Discovery could Endanger T.Rex Name." The Associated Press.)

In short, could M. gigas be a nomen oblitum? Maybe, depending on the meaning of "valid" and if somebody gets up the nerve to actually publish the case. Is Manospondylus a nomen oblitum as of right now? Definitely not, and it remains the valid senior synonym of Tyrannosaurus until and unless someone acts as revisor to the contrary.

Addendum: Just for fun, I looked up "valid" in the ICZN's glossary. Who better to determine what the ICZN means by valid than the ICZN? Here's the entry:
valid, a. (validity, n.) Of an available name or a nomenclatural act: one that is acceptable under the provisions of the Code and, in the case of a name, which is the correct name of a taxon in an author's taxonomic judgment.

Since the Code does not formally recognize nomina dubia as invalid names (or at all, really), this seems to indicate that M. gigas was considered valid by all those authors in the 20th century, at least under the ICZN's definition. Matthew and Brown, for example, did not consider M. gigas an invalid name (a junior homonym, improperly coined, etc.), just non-diagnostic. Which as far as the rules are concerned, is A-OK. Sorry kids, barring an act of ICZN, M. gigas looks like it's on solid footing as a currently valid name.

Friday, September 3, 2010

Balaur bondoc: Dodo-Raptor?

Here's a really interesting idea floated by Andrea Cau (with help from Mickey Mortimer, Ville Sinkkonen, Rutger Jansma and Zach Miller) over at his Theropoda blog.

Everyone is making a big deal about Balaur bondoc, the apparently double-sickle clawed dromaeosaur. The double sickle idea comes from the very strange nature of the foot (close-up image in the last post, linked above).

Above: Fossils of Balaur bondoc reconstructed as a standard dromaeosaur. Credit: PNAS/AP.

The first sickle claw is present on the first toe. Normally, in non-avian theropods, the first toe is small and placed high on the foot, like the dew claw of a dog. Basically, it's vestigial. However, in lineages where the first toe evolves some kind of use, the entire metatarsal supporting the toe tends to descend, placing the first toe at the same level as the others. This is seen in two lineages of theropod: birds, where the first toe is used for perching, and therizinosaurs, where it's been re-adapted for walking. Animals that use four toes in walking (rather than having four toes but only using three) are called functionally tetradactyl.

So, did Balaur not use its enlarged first and second toes to kill prey as in other dromaeosaurs, but simply as extra walking digits, as in therizinosaurs? Balaur is certainly built like a therizinosaur, with short, stocky hind limbs and very weird hips. The hip bones of Balaur, as you can see in the image above, are extremely swept back. Some of this may be due to crushing, but probably not all. Normally, such a hip arrangement is seen only in herbivorous dinosaurs, which need to clear out space in the torso for their expansive, plant-fermenting guts.

Tim Williams on the DML has also pointed out that the atrophied hands with reduced third finger and fused wrist elements are also indicators of decreased predatory ability. The only other dinosaurs I can think of off hand that have such reduced third fingers are avialans and the herbivorous Caudipteryx (and, of course, alvarezsaurids and tyrannosaurids, but for different reasons). Avialans and Caudipteryx are the only ones that retain fairly normal hand proportions while shrinking the third finger.

Much has been made of the fact Balaur lived on isolated Romanian islands, and that the "island rule" probably had a lot to do with its weird anatomy. Could similar effects have led to this line of dromaeosaurs becoming fully herbivorous? Weirder things have happened to island dinosaur lineages. Just look at the kiwi.

The parallels between Balaur and therizinosaurs are hard to ignore, but obviously it would be helpful to have some skull material before definitely drawing any conclusions about its diet. In the mean time, check out the cool reconstruction Andrea included in his post for what a therizinosaur-mimicking dodo-raptor may have looked like.