Adding the Denver Pteranodon: The origin of the long crest

Updated September 20 with reception of jpegs of the specimen.

Earlier we looked at the wide variety of Pteranodon crests (Fig. 1). Placed in a phylogenetic analysis the skulls show a gradual evolution from smaller crestless species close to Germanodactylus all the way up giant crested species with a wide variety of crest shapes, followed by a reduction in size preceding extinction (lower right corner of figure 1). Contra tradition, this analysis demonstrates no gender identify and no juvenile identity based on size and crest size — other than a Pteranodon juvenile, nicknamed Ptweety (pictured behind the Q specimen, YPM 2594, which it most closely resembles.

Previously not included on this chart was the Denver specimen, DMNH 1732 (Fig. 1), which sports a complete, but short crest of the long-crest variety, and is otherwise every bit as large as other giant Pteranodon species. Details on this rarely imaged skull have arrived.

 

Figure 2. The DMNH specimen is in color, nesting between the short crest KS specimen and the long crest AMNH specimen.

Figure 2. The DMNH specimen is in color, nesting between the short crest KS specimen and the long crest AMNH specimen.

This chart shows the gradual evolution regardless of gender.
The Denver specimen might be a short-crested female, but remember, you can’t evolve a long or tall crest without first going through a small or short crest phase. That’s why we’ll have to wait for other clues* before we start assigning gender and age to various specimens of Pteranodon. The skulls all fit into a very neat completely resolved phylogenetic series here, with no two pairing off as male and female… yet.

*As we learned earlier, Bennett’s 1992 purported female Pteranodon pelvis,  KUVP 993, is morphologically just a big Nyctosaurus.

References
Bennett SC 1992. Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests. Journal of Vertebrate Paleontology 12: 422–434.

3 thoughts on “Adding the Denver Pteranodon: The origin of the long crest

  1. Male and female “pairs” don’t form off in phylogentic trees. What gets resolved is a clade of males and a clade of females. Not “pairs”.

    • I can’t imagine that anyone has actually done a male/female phylogenetic tree. But note in Pteranodon, the morphologies do not produce male and female paired species, which would be expected if small crests were females. Here small crests are just transitional between no crests and giant crests, among several other traits, of course.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.