Really? We get to see that Greg Paul was really really right about that whole “neoflightless” thing? In case you hadn’t heard — and if you’re reading this blog, you most likely have — Archaeopteryx lithographica, famed urvogel, has been dethroned as, well, the urvogel.
Xu Xing and several of his students and colleagues have named a new taxon, Xiaotingia zhengi, from a specimen (mainslab, missing the counterslab) that was recovered from northeastern China and from sediments in the late Mesozoic. They may or may not predate the arrival of Archaeopteryx lithographica. Moreover, a phylogenetic analysis of over 300 characters and nearly 90 taxa, an adaptation of the Theropod Working Group analysis supports the placement of Archaeopteryx lithographica outside of the stem leading to birds where it splits from the Dromaeosauridae and Troodontidae (Deinonychosauria). This position, effectively at the base of a clade including it and Deinonychosauria, has been linked to Greg Paul’s theory that “Archie” is, in fact, a tiny flighted dromaeosaur that gave rise to bigger-bodied, flightless (hence “neo”-flightless).
Now, personally, I’m interested in something else about this specimen, which I will get to in a while, perhaps a hint of which is in this blog’s general theme. I wanted to take this post to discuss something that came up tangentially.
Denver Fowler has commented here in regards to Raptorex kriegsteini, and it was further mentioned not that long ago here by both Denver and Mike Taylor on the Dinosaur Mailing List, both because of LH PV18 (type of the aforementioned specimen) and others. A while back, I mentioned the case of two pterosaur specimens, KJ1 and KJ2, which may have a large effect on the biomechanics of cranial crests and the taxonomy of the “nyctosaurids,” pterosaurs similar to Pteranodon longiceps and kin. The provenance of STM 27-2, holotype of Xiaotingia zhengi Xu et al. (2011) is another example. From the SOM of the latter paper:
The holotype and only known specimen of Xiaotingia zhengi was acquired by the Shandong Tianyu Museum of Nature from a fossil dealer, according to whom the specimen was collected in the Linglongta area, Jianchang, western Liaoning, China. However, he could not provide accurate information as to the quarry in which the specimen was collected. [...] Although the slab preserving the Xiaotingia zhengi holotype is most similar to the fossil-bearing beds of the Tiaojishan Formation, it is difficult to distinguish between Tiaojishan and Yixian shale slabs on the basis of macro-sedimentary features. Discoveries of additional specimens with definite locality information, or micro-sedimentary analysis of the slab preserving the Xiaotingia zhengi holotype, will help to resolve this issue.
Fowler et al. (2011) especially raised issues with Sereno et al. (2009) on the provenance of LH PV18 due to the lack of certainty and the apparent contradictory statements of fossil dealers. If such an issue were to matter, the above specimen would be among them. The authors are careful, however, as they make little in the biostratigraphal context (unlike Sereno et al.) which allows the specimen to essentially speak for itself. Here, we are once again faced with the question of the value of material which we cannot reliably date, and whether that date actually matters.
My personal feeling is that the specimen is of value regardless of its provenance. In a way, this means that material acquired from the Tuscon Rock and Gem Show, itself often in controversy over such specimens, can also be of such value. It has much to do with specimens like this one, which AMNH preparator Jason Brougham brought up on his blog here, for different reasons:
or these ones:
These specimens are valuable, effectively lost to Science, they tell us nothing. But as casts, as surficial data, they can be used for other things, such as datapoints in broader analyses, morphological variation data, etc. They cannot be cut up, scanned under computed tomography or magnetic resonance imagine, or sampled for microtextural analyses, but their gross anatomy can be assessed (to the degree that the cast and thus unprepared “matrix” allows). Should we have the opportunity, this material qualifies other work, and is thus of importance, although not to the degree that having the actual specimen in an institution (and the mantra “It belongs in a museum!” so applies in this case). It cannot replace the original, not by a long shot, but casts are valuable for researchers even when the original is available, because that material may be too large to handle, too rare or valuable to cut up or into, or too fragile to touch, expose, etc., as in the famous Iguanodon bernissartensis skeletons extracted from the Bernissart coal mines in Belgium, which “suffer” progressive pyritization.
But this is only the tip of the ‘berg, as it were: Here, I discuss real, stable, preserved specimens which have been lost through the human agency of desiring to keep private and hidden what are ostensibly “cool” toys, but are valuable pieces of information to scientists. But there’s another type of “lost” specimen, and that’s the destroyed specimen. I will get to that in a bit.
Fowler, D. W., Woodward, H.N., Freedman, E.A., Larson, P. L. & Horner, J. R. 2011. Reanalysis of “Raptorex kriegsteini“: A juvenile tyrannosaurid dinosaur from Mongolia. PLoS ONE 6(6):e21376.
Sereno, P. C., Tan L., Brusatte, S. L., Kriegstein, H. J., Zhao X.-j. & Cloward, K. 2009. Tyrannosaurid skeletal design first evolved at small body size. Science 326:418-422.
Xu X., You H.-l., Du K. & Han F.-l. 2011. An Archaeopteryx-like theropod from China and the origin of Avialae. Nature 475:465-470.