FIgure 1. Dinosaurs rediscovered by MJ Benton book cover.
Dr. Stephen Brusatte wrote
on the cover: “If you want to know how we know what we know about dinosaurs, read this book!”
‘Amazon Customer’ wrote
at the book’s website, “Nice production, but highly biased and speculative.” (more below)
Dr. MJ Benton is professor of vertebrate paleontology and head of the Palaeobiology Research Group at the U of Bristol, England. He has written more than fifty books, including the standard textbooks in palaeontology.
From the intro:
“One by one the speculations about evolution, locomotion, feeding, growth, reproduction, physiology, and, finally, color have fallen to the drive of transformation. A new breed of dinosaur palaeobiologist replace the older ones, and they have applied a hard eye to the old speculations. Smart lateral thinking, new fossils, and new methods of computation have stormed the field.”
Scleromochlus (Fig. 2) is not mentioned. Benton 1999 promoted this genus close to the origin of pterosaurs and in the book he maintains that pterosaurs remain close to the origin of dinosaurs with no further explanation. Evidently Scleromochlus is no longer in favor. Nearly 20 years ago Peters 2000 invalidated the pterosaurs-close-to-dinosaurs = ornithodire hypothesis by testing Benton’s cladogram and three others by simply adding taxa overlooked and poorly scored by Benton and other prior authors. But let’s move on…
Figure 2. According to the AMNH, Scleromochlus is “one of the closest early cousins of pterosaurs.” Oddly, they gave it the skull of Longisquama. Note the vestigial hands. These cannot elongate to become wings and pedal digit 5 is a vestige that cannot elongate to match basal pterosaurs.
Chapter 1 — Origin of the Dinosaurs
Even in 2019, Benton writes, “One thing is known for sure: the dinosaurs originated during the Triassic period, between 252 and 201 million years ago. Nearly everything else is uncertain.” This is not exactly a teaser, because it does not jive with what Benton writes earlier (Benton 1999) and later (see below).
that he raised traditional eyebrows back in 1983 when he suggested the old standard model of one group/clade giving way to another should be replaced with a scenario in which new clades only appeared and/or radiated after an extinction event. This view makes great sense and is supported by strong evidence. Ironically, Benton reports, “This new idea of mine was probably quite annoying for the established paleontologists.” Now that he’s older, the tables have turned and it’s Benton’s turn to be annoyed. Philosophically he has taken the place of his 1983 opponent and mentor, Dr. Alan Charig in that Benton now refuses to consider, test or replace invalid scenarios with new ones.
Let’s not forget…
in his unbiased youth, Benton 1985 used an early form of phylogenetic analysis to show that pterosaurs were sister taxa to lepidosaurs, closer to lizards than to dinosaurs by a long shot. Now that this hypothesis has become heterodox, he and others have avoided it ever since by selective deletion of pertinent taxa.
Figure 2. Cladogram from Benton 1985 in which he nests pterosaurs closer to lepidosaurs than to dinosaurs and other archosaurs. Lots of confusion here due to taxon exclusion going back to the advent of Reptilia (= Amniota).
A subchapter follows
on the lepidosaur rhynchosaur, Hyperodapedon (Benton 1983), where Benton first published on taxa he was given to worth with, but made the phylogenetic mistake of lumping rhynchosaurs with archosauromorphs. This was due to taxon exclusion.
The next subchapter, “What was the first dinosaur?”
Benton correctly identifies one of the first dinosaurs as Herrerasaurus. That agrees with the large reptile tree (LRT, 1562 taxa) which uses the last common ancestor method for determining clade member inclusion.
Figure 3. Basal bipedal ‘dinosauriformes’, from Lagerpeton through Marasuchus, Lewisuchus, Asilisaurus, Sacisaurus and Silesaurus, according to Nesbitt (2011). The LRT does not support this listing or sequence.
Then Benton reports on the poposaur
dinosaur-mimic, Silesaurus (Fig. 3), the Early Triassic ichnite Prorotodactylus, and another poposaur dinosaur-mimic, Asilisaurus (Fig. 3). Benton reports, “The discovery of Asilisaurus unequivocally re-dated the origin of dinosaurs back from 230 to 245 million years ago, or older.” There is little to differentiate Asilisaurus from Silesaurus. Both remain poposaurs and dinosaur-mimics, unrelated to the dinosaurs, except through basal bipedal crocodylomorphs, which Benton avoids. So, taxon exclusion strikes Benton, once again.
Quote here, an anonymous, but well-educated, review from Amazon.com:
“Dinosaurs Rediscovered is an engagingly written and highly personalized account of dinosaurs, generally covering the field’s perceived advances from 1980 to the present. The publisher Thames & Hudson did an outstanding job in producing the book, formatting, and in the selection of paper.
“The author notes that the field transformed from 1984 onwards by cladistic methods, and the resulting phylogenetic trees or cladograms have thus become the “basis” for evaluating evolutionary models and all things dinosaurian, including anatomical reconstructions, physiology, behaviour, etc. The work described is rather restricted, with most emphasis given to the University of Bristol’s vertebrate palaeontologists, often ignoring important discoveries from other groups, and regrettably ignoring most conflicting evidence. The most egregious is the complete omission of any discussion of the persisting problem of dinosaur/avian digital homology.
“Benton begins with the discovery (in his laboratory) of microsomes known as melanosomes from SEMs of fibers from the back of the small theropod Sinosauropteryx, that were described as “proto-feathers” back in 1998. However, there was never any evidence that the fibers had any feather affinity, and many who studied the specimens found an external coating of small tubercular scales above the layer of fibers —- since prepared away and lost! It is clear, however, that the fibers called proto-feathers or “dino-fuzz” were beneath the skin and therefore not feathers. Too, as South African palaeontologist Lingham-Soliar showed in several important papers (not cited) the structures called melanosomes cannot be interpreted from the scanning electron micrograph (p. 8) as being within the fibers. Speculation!
“Plate V shows a fuzzy Sinosauropteryx with a ring tail like that of a civit or ring-tailed cat!! Then there is an outlandish image of a reconstruction of the Jurassic urvogel Anchiornis (incorrectly called a troodontid, see Pei ref below), as a terrestrial animal; but the feathers emanating from the legs and feet would have been a hindrance in ground locomotion. New fossil images (Pei et al., 2017 AMNH Bull 411, 66 pp) show claws consistent with tree-trunk climbing, similar to those of other urvogels. Plate VI shows photos of a “dinosaur tail” in amber, but there is NO evidence it is from a dinosaur and is most likely an enantiornithine bird.
“The section on dinosaur evolution is straight forward, but laden with speculation, and given the massive convergence among various archosaur lineages during the Triassic it is difficult to have full faith in the interpretations; and authors from Cambridge and the British Museum have questioned the time-honored phylogeny (pp. 82-84).
“Most of the remainder of the book is a romp through the various dinosaurian groups, with comments on everything from brains and internal organs to behaviour. Archaeopteryx is depicted as an earth-bound runner (p. 112), with open wings (like no living avian cursor – e.g. capercallie, chicken, etc.), despite the fact that Manchester’s Derek Yalden showed conclusively that the urvogel’s claws were those of a trunk-climber, quite similar in structure to those of woodpeckers and climbing mammals.
“Benton notes (122) without reservation that Sinosauropteryx “was the first dinosaur to have its feather colour determined”—-and on page 123 he shows a feathered Caudipteryx with avian wing feathers and notes “it is clearly a theropod and not a bird” in contrast to numerous papers arguing that it is a secondarily flightless bird. If not, flight feathers, a perfection of aerodynamic engineering, would have to evolve in a non-flight context, a real stretch of biological thought!
“In chapter 5 “Jurassic Park” he seems ambivalent about reconstructing dinosaurs from ancient DNA, although most would agree that it is impossible. Certainly Mary Schweitzer’s supposed discovery of T. rex blood vessels and proteins has been firmly refuted. He comments on small genome size in birds and dinosaurs, but the studies conflated the two groups, and small genome size is to be found in flying animals: bats, pterosaurs and birds. Growth studies on dinosaurs are discussed but much of that has recently been brought into question. Allosaurus (188) and Tyrannosaurus, with no evidence, are shown with a feathered coat! Diplodocus (210) is shown with neck high in the air, a posture disputed by computer-generated imaging. Benton appears to favor the model of flight origin of Dial and Heers, but such a model requires a fully developed flight apparatus, and both putative dinosaurian ancestors of birds, urvogels, and even archosaurian antecedents, all lacked the pectoral architecture to enact this model. It just will not work. Much speculation!
“Finally, although there is no citation in the text, the monolithic bibliographic listing in the section on ‘Further Reading’ is alarming; it appears highly selected to bolster the Bristolian view of dinosaurs, while ignoring any contrary views, many of which are supported by solid scientific data. Most disturbingly, the discoveries by Chinese palaeontologists, especially those at Beijing’s Institute of Paleontology and Paleoanthropology, which in reality propelled the recent revolution in our knowledge of dinosaur/bird evolution is largely ignored.”
Dr. Benton’s new book gave us old, misguided and too often invalid information. In 2019 we know better how taxa are related to one another and Benton should have known better, too. Taxon exclusion (= phylogenetic context) seems to be his number one problem because his descriptions and illustrations of specimens are typically excellent. After messing up on his first paper (removing rhynchosaurs from rhynchocephalians), Benton’s reputation and output continue to be tarnished with his latest book and many of his recent papers all due to taxon exclusion. On the other hand, and in the present climate, Dr. Benton understands there is no consequence for ignoring new hypotheses. If only he could recall what it was like for him back in 1983, trying to promote his own new scenario to the establishment.
Those paleo professionals who wrote glowing reports
for this book should also have known better, but allegiance can sometimes trump good science. Author and paleontologist, Stephen Brusatte (quoted above) was a student at Bristol, where Benton teaches.
A wide gamut phylogenetic analysis based on specimens
is a necessary ingredient before, during and after any specimen description. It remains the one and only way to minimize taxon exclusion.
Benton MJ 1983. The Triassic reptile Hyperodapedon from Elgin, functional morphology and relationships. Philosophical Transactions of the Royal Society of London, Series B, 302, 605-717.
Benton MJ 1985. Classification and phylogeny of diapsid reptiles. Zoological Journal of the Linnean Society 84: 97-164.
Benton MJ 1999. Scleromochlus taylori and the origin of the pterosaurs. Philosophical Transactions of the Royal Society London, Series B 354 1423-1446. Online pdf
Benton MJ 2019. Dinosaurs rediscovered. Thames & Hudson.
Nesbitt SJ, Sidor CA, Irmis RB, Angielczyk KD, Smith RMH and Tsuji LMA 2010. Ecologically distinct dinosaurian sister group shows early diversification of Ornithodira. Nature 464 (7285): 95–98. doi:10.1038/nature08718. PMID 20203608.
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos 7:11-41.
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.