The Masthead – WP#17

Pterosaurs represent an unusual group of diverse archosauromorphan vertebrates, characterized by large skulls, light body plans, and extremely elongated arms. Among them, there were the small anurognathids who sported large, wide heads and very long wings; gar-toothed, slender-snouted “rhamphorhynchids” (a likely paraphyletic grade); long-necked, long-snouted, many-toothed ctenochasmatoids; the gigantic pteranodontids and azhdarchids, some sporting extremely large skulls for their size and the latter sporting extremely long necks; anhanguerids, with their keel-snouted jaws and tapejarids with their high, triangular(-ish) crests.

Among the pteranodontids, a peculiar set of skeletons produced a typical Pteranodon-like skull, but with very, very odd bifurcating thin crests. Referred to Nyctosaurus [1] as based on an unresolved, and possibly unique species, the specimens that comprise this study are currently privately owned. This issue tends to lead to discussions on whether scientists should study or even mention privately-owned material, as well as the wealth of information confined to localized and unseen material held in private hands due to the prestige of collecting, owning, and sometimes even stealing fossils for the sake of notoriety or greed. While not all of these characteristics apply to Bennett’s [1] specimens (labeled KJ1 and KJ2), they elicit the need to examine ethical practices for scientists who discuss material not available for re-examination in case of need to verify observations (which generally amounts to heresay), as well as private collectors who may spend millions of dollars to acquire a large fossil, often publically, only to then let it disappear, taking with it any potential information it may elide.

In many ways, since their publication, KJ1 and KJ2 have become mastheads in several things, prominent pieces in both the reconstruction of pterosaurs, the aerodynamic options of their cranial shape [2], and in the collection and reporting of private specimens.

Nyctosaurus, inferred to be an as yet unknown species, from two privately-held specimens. (After Bennett, 2003.) Based on the possible but considered unlikely nasal crest of Nyctosaurus bonneri (Bennett, pers. com., believes this to be an artefact), I put a soft-tissue crest on the snout, as well. This is not shown below.

Nyctosaurus, projecting the possible presence of a soft-tissue crest between the elongated branches of the bifurcate crest (he shown longer on the horizontal ramus than in the above illustration). A narrow-chord wing is projected based on discussions from various authors, although some other authors have argued against such a wing in generally all pterosaurs.

[1] Bennett, S. C. 2003. New crested specimens of the Late Cretaceous pterosaur Nyctosaurus. Paläontologische Zeitschrift 77:61-75.
[2] Xing L., Wu J., Lu Y., Lü J.-c. & Ji Q. 2009. Aerodynamic characteristics of the crest with membrane attachment on Cretaceous pterodactyloid Nyctosaurus. Acta Geologica Sinica 83(1):25-32.

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4 Responses to The Masthead – WP#17

  1. “Nyctosaurus, inferred to be an as yet unknown species”

    Correct me if I’m wrong, but my understanding from Bennett’s paper was that they’re not necessarily a new species, just that Nyctosaurus is in need of taxonomic revision, and the existing named species need to be re-diagnosed, so it while it probably belongs to one of the existing species (if there are more than one), it’s just impossible to tell which at this point.

    • I’m not sure I got that Bennett felt it would belong to one of the existing species, only that he explicitly did not attempt to identify it taxonomically compared to the other specimens/species due to the fact of its preservation; absence of the crest in other skulls of Nyctosaurus has not been linked to taphonomy nor taxonomy, and the identification of Nyctosaurus sp. is hesitant. It may not even belong to Nyctosaurus, should one restrict that to the two likely “valid” species, gracilis and nanus.

  2. Christopher says:

    I was under the same understanding as Matt. What features suggest to you that its something different than gracilis or nanus? Given what we know of Pterosaur ontogeny, the simple presence/absence of a crest isn’t or at least shouldn’t be considered diagnostic. And other than the crests there really is nothing that isn’t a taphonomic artifact that could be used to elevate these specimens to something other than gracilis or nanus, and certainly not to a genus of their own.

    • I actually have no idea if it is or isn’t a new species: I said that it was an unknown species, which is just as true (hence Bennett’s designation), although I understand this can imply “unknown” = “new”; Bennett deliberately did not refer it to a know species, much less a new one, and it may be questionable to refer it to Nyctosaurus due to the unavailability of the specimens (casts aside — plastoholotypes may be useful for the purpose of taxonomy [see Kakuru kujani]).

      All Nyctosaurus may be gracilis, or gracilis may be a nomen dubium along with bonneri or nanus, dependong on the quality of the value of proportions between the specimens. If only the crested specimens are distinct enough from specimen to specimen, as visual-displaying features are the primary means of discerning Pteranodon species, we may have only one taxon … or five.

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