From Berkeley: pterosaur origins and whale evograms

Professor Kevin Padian (U of California, Berkeley)
has been a champion for evolution over the past several decades. In the 1980s I became acquainted with him when he was the science expert for my first book, Giants.

The following one hour video on YouTube caught my eye.
Professor Padian brilliantly discusses how school districts dealt with invading Creationists. Padian has been leading the charge on many fronts regarding evolution. Unfortunately, he has stayed in his tent sipping tea regarding the origin of flight in pterosaurs (Padian 1985), and the origin of whales, as you’ll see below.


From the page on pterosaur flight:
“Pterosaurs are thought to be derived from a bipedal, cursorial (running) archosaur similar to Scleromochlus in the late Triassic period (about 225 million years ago). Other phylogenetic hypotheses have been proposed, but not in the context of flight origins. The early history of pterosaurs is not yet fully understood because of their poor fossil record in the Triassic period. We can infer that the origin of flight in pterosaurs fits the “ground up” evolutionary scenario, supported by the fact that pterosaurs had no evident arboreal adaptations. Some researchers have proposed that the first pterosaurs were bipedal or quadrupedal arboreal gliders, but these hypotheses do not incorporate a robust phylogenetic and functional basis. The issue is not yet closed.”

This comes 20 years after Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama (Fig. 1) were added to four previously published phylogenetic analyses and all nested closer to pterosaurs than any tested archosaur (Peters 2000). Aspects of this topic were reviewed here in 2011 and here in 2015.

pterosaur wings

Figure 2. Click to enlarge. The origin of the pterosaur wing from Huehuecuetzpalli (B) to Cosesaurus (C) to Sharovipteryx (D) to Longisquama (E) to the basal pterosaur, Bergamodactylus (F and G).

The same webpage notes:
“Pterosaurs also had a bone unique to their clade. It is called the pteroid bone, and it pointed from the pterosaur’s wrist towards the shoulder, supporting part of the wing membrane. Such a novel structure is rare among vertebrates, and noteworthy; new bones are unusual structures to evolve — evolution usually co-opts bones from old functions and structures to new functions and structures rather than “reinventing the wheel.”

This comes 11 years after Peters 2009 showed the pteroid was not unique, but a centralia that had migratred medially in Cosesaurus (like the panda’s ‘thumb’). Likewise, the not-so-unique pteroid was co-opted from old functions, contra the Berkeley evolution page.

The same webpage notes:
“Pterosaurs had other morphological adaptations for flight, such as a keeled sternum for the attachment of flight muscles, a short and stout humerus (the first arm bone), and hollow but strong limb and skull bones.”

We’ve known since Wild 1993 that what Padian 1985 called a keeled sternum is actually a sternal complex composed of a fused interclavicle + clavicle + single lepidosaur sternum (Fig. 3) after migration over the interclavicle.

Tritosaur pectoral girdles demonstrating the evolution and migration of the sternal elements to produce a sternal complex.

Figure 3. Tritosaur pectoral girdles demonstrating the evolution and migration of the sternal elements to produce a sternal complex.

25 years ago, when I first met Kevin Padian and Chris Bennett, they both impressed upon me, at the same time and during a single conversation, the need for a proper phylogenetic context before making any sort of paleontological hypothesis. That’s when MacClade and PAUP were still ‘newish’. That’s why you might find it ironic that neither Padian nor Bennett have ever tested the addition of the four key taxa in figure 3 to prior published analyses that included pterosaurs, as I did in Peters 2000.

On the second topic of whale evolution:
Padian’s ‘evogram’ (evolution diagram) simply lacks a few key taxa. Odontocetes don’t arise from hippos. Only mysticetes do. Here (Fig. 4) a few missing transitional taxa are added to the existing evogram. Likewise the outgroup for Pakicetus and Indohyus now include overlooked tenrecs and leptictids. They look more like Indohyus than the hippo because microevolution becomes more apparent when pertinent taxa are added. Otherwise it’s a big morphological jump from hippos to Indohyus. Adding taxa makes ‘the jump’ much smaller as the LRT has demonstrated dozens of times. No one should be afraid to simply add taxa.

Figure w. Whale evogram from Berkeley website and what happens when you add taxa based on the LRT.

Figure 4. Whale evogram from Berkeley website and what happens when you add taxa based on the LRT. Two frames change every 5 seconds. It’s not good that the outgroup to the slender Indohyus is the massive Hippopotamus. Frame two repairs that inconsistency with a little microevolution.

As you can see,
the University of California at Berkeley no longer stands at the vanguard of paleontology. Rather it has been promoting traditional myths on its website for the last twenty years.

According to Padian’s online talk (above):
“Just because you have  a degree in science does not mean you’re a scientist. Scientists are people who do research, publish peer-reviewed research as a main part of their living.”

That’s good to know. Of course, it doesn’t help if one suffers from the curse of Cassandra. On that point, I’m not asking anyone to ‘believe the LRT’, but to simply add taxa to your own favorite cladograms, as Peters 2000 did to four different previously published studies that each had their own taxon and character lists. That’s what the large reptile tree has continued to do over the last 9 years. Others who have added taxa and recovered results confirming those recovered by the LRT are listed here. The pair of PhDs who decided those results should be erased are listed here.

Ingroup scientists who attempt to exclude outgroup scientists is a common thread in human history. Here’s a YouTube video trailer for an upcoming Marie Curie biography. I’m sure you all know the story of her pioneering work in radioactive elements.

Padian K 1985. The origins and aerodynamics of flight in extinct vertebrates. Palaeontology 28(3):413–433.
Peters D 1989. Giants of Land, Sea and Air — Past and Present. Alfred A. Knopf/Sierra Club Books
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2009.
A reinterpretation of pteroid articulation in pterosaurs.
Journal of Vertebrate Paleontology 29: 1327-133.
Wild R 1993. A juvenile specimen of Eudimorphodon ranzii Zambelli (Reptilia, Pterosauria) from the upper Triassic (Norian) of Bergamo. Rivisita Museo Civico di Scienze Naturali “E. Caffi” Bergamo 16: 95–120.

2 thoughts on “From Berkeley: pterosaur origins and whale evograms

Leave a Reply

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

You are commenting using your 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.