My first book, this was a labor of love. I wrote The Bare Bones for my students and to make anatomy and paleontology more accessible to non-experts.


The Bare Bones - Synopsis

What can we learn about the evolution of jaws from a pair of scissors? How does the flight of a tennis ball help explain how fish overcome drag? What do a spacesuit and a chicken egg have in common? Highlighting the fascinating twists and turns of evolution across more than 540 million years, paleobiologist Matthew Bonnan uses everyday objects to explain the emergence and adaptation of the vertebrate skeleton. What can camera lenses tell us about the eyes of marine reptiles? How does understanding what prevents a coffee mug from spilling help us understand the posture of dinosaurs? The answers to these and other intriguing questions illustrate how scientists have pieced together the history of vertebrates from their bare bones. With its engaging and informative text, plus more than 200 illustrative diagrams created by the author, The Bare Bones is an unconventional and reader-friendly introduction to the skeleton as an evolving machine.

“Bonnan combines wit and passion with the sensibilities of a talented instructor in this encyclopedic tour of the vertebrate skeleton . . . accessible even for those without a background in anatomy."
"No bones about it, a text like The Bare Bones was sorely needed in the popular literature of vertebrate paleontology. Matthew Bonnan's tome on the evolution, form, and function of the vertebrate skeleton may seem daunting in size, but it is written in an enjoyable and readable fashion that will absolutely delight all sorts of readers from expert to soon-to-be-expert."
- Shaena Motanari, paleontologist & science journalist
“The Bare Bones covers a lot of ground, much of it familiar, but it is a remarkably fun book to read. Bonnan avoids the most intimidating jargon of anatomy and phylogenetics, elucidating the necessary concepts through clear writing and clever application of nonbiological analogies. He is forthcoming about the simplifications and omissions that make the volume so readable, and his conversational style and wit make this an unintimidating yet highly informative book that would work wonderfully in college courses.”
-Christine A. Andrews, University of Chicago
“In accessible though often dense prose, Bonnan conveys a huge amount of frequently fascinating detail that will make his book a
gold mine for students. ... if you are interested in your
skeleton as a machine, this is the place to come."
- Ian Tattersall, Curator Emeritus, American Museum of Natural History
"Matthew Bonnan’s first book,
The Bare Bones, does an amazing job of connecting form with function without sacrificing the science."
- Thomas Hegna, Fredonia, State University of New York
“A clear, largely jargon-free retelling of one of the greatest stories in evolution―the rise of vertebrates―that should have broad appeal. It integrates the facts and principles that underlie evolutionary theory by taking a common-sense approach that doesn't talk down to the reader.”

Updates & Corrections

Vertebrate paleontology is an ever-changing field, and I am only human, which means that since the publication of the book in 2016 we have learned more about vertebrate evolution and some corrections are warranted.

Last Updated 9/5/2020

  • On p. 93, Figure 6.2, the pectoral girdle for the placoderm is mislabeled. The top portion is indicated as the “scapula” and the lower portion is labeled as the “coracoid.” These should have been labeled “dorsal pectoral girdle” and “ventral pectoral girdle.” The pectoral girdle of placoderms is comprised of several different bones whose homologies to those of other jawed vertebrates are uncertain. For example, portions of the pectoral girdle in placoderms may be comprised of a cleithrum and clavicle (see Min and Schultze [2001] for a discussion of this issue). To simplify discussion, I did not go into these particular details in the book. In placoderms, the scapulocoracoid is present and the pectoral fin articulated with it, but is a smaller bone sandwiched within the pectoral girdle bones. The approximate position of the scapulocoracoid is correctly identified in the “Jaw Opening” portion of Figure 6.2. Min, Z. and H.-P. Schultze. 2001. Interrelationships of basal osteichthyans; pp. 289-314 in P. Ahlberg (ed.), Major Events in Vertebrate Evolution. New York: Taylor and Francis.

  • On p. 110, I mistakenly stated that great white sharks and Megalodon are members of Carchariniformes. They are members of Lamniformes.

  • Point of clarification. On p. 134, I say, “The pelvic fins, in their place directly ventral to the pectoral fins, serve a similar purpose, directing water under the teleost fish as it rapidly slows and creating a downward force to counteract the upward force generated near the tail (Drucker and Lauder, 2003).”

    • The citation should have been placed in a previous paragraph to indicate that Drucker and Lauder (2003) discuss the function of pectoral fin braking in teleost fish. Drucker and Lauder (2003) note that during braking, trout recruit fins caudal to the center of mass, possibly to inhibit this somersaulting. The airdam analogy with the pelvic fins is my analogy, not theirs.

    • It is Harris (1938) who discusses the function of pelvic fins in creating a downward force to counteract the rise and pitch of the fish, and this article should also have been cited in the book: Harris, F.E. 1938. The role of fins in the equilibrium of the swimming fishes II: the role of the pelvic fins. Journal of Experimental Biology, 15:32-47.

    • Drucker and Lauder (2003) show that the more ventrally located pectoral fins of rainbow trout, when used in braking, can create a large torque around the center of mass. Their data support a previously untested hypothesis by Breder (1926) that a somersaulting motion can occur when the pectoral fins are utilized for braking in some fish.

    • When I said “… the upward force generated near the tail,” it would have been clearer to say, “… the momentum of the fish.”

  • On p. 167, “All tetrapods have evolved some sort of eyelids, and have adapted portions of some of the eye-moving muscles to help them blink (Young, 2008).” Whereas the paper by Young (2008) (Young, G. C. 2008. Early Evolution of the Vertebrate Eye—Fossil Evidence. Evolution: Education and Outreach 1:427–438) is excellent, this was a mis-citation. The work by Zhu and Keifer should have been cited instead: Zhu, D., and J. Keifer. 2004. Pathways controlling trigeminal and auditory nerve-evoked abducens eyeblink reflexes in pond turtles. Brain, Behavior and Evolution 64:207–222.

  • On pp. 205-207, I discuss binocular vision in frogs. Although I cite Pough et al. (1998) and Liem et al. (2001) in regard to frog binocular vision (they discuss vision in frogs but not binocular vision itself), I should have cited Howard and Rogers (1995) instead: Howard, I. P., and B. J. Rogers. 1995. Binocular Vision and Stereopsis. Oxford University Press, New York, 736 pp.

  • On p. 218, the first sentence of paragraph 2 says, “Two intriguing aspects of Balanerpeton are …” This should say, “One intriguing aspect of Balanerpeton is …“

  • On p. 258, I relay the story of bearded dragon intelligence by Kis, Hube, and Wilkinson (2015). I state, “… when beardies that had not been trained to open the trapdoor were placed in the same enclosure with those who were …” This is a misstatement. What I should have said was, “… when beardies that had not been trained to open the trapdoor viewed those lizards demonstrating the behavior on a TV screen …”

  • On p. 266, I erroneously attributed the lack of an external ear and the ability to hear in the tuatara to Pough et al. (1998) and Benton (2005). Although both texts provide ample information on the tuatara, neither discuss the ear in this animal. The correct citation should be Gans and Wever (1976): Gans, C., and E. G. Wever. 1976. Ear and hearing in Sphenodon punctatus. Proceedings of the National Academy of Sciences 73:4244–4246.

  • On p. 329, when referring to the sclerotic ring of birds, I state, “Birds rely to a great extent on the sclerotic bones to squeeze and distort their lenses …” This should have read, “Birds rely to a great extent on the sclerotic bones as a base from which eye muscles squeeze and distort their lenses …”

  • On p. 379 in Figure 18.11 and on p. 380, I state that among the features Deinonychus shares with birds is the presence of a furcula. Whereas Deinonychus must have had a furcula given its place on the dinosaur family tree (for example, its close relative Velociraptor certainly does), no specimens of Deinonychus have preserved a furcula. We now typically show Deinonychus with a furcula because it likely had one.

  • On p. 416, I discuss the importance of the biceps femoris muscle in mammals as a thigh extensor and knee flexor, as well as its role in jumping cats. However, the paper by Harris and Steudel (2002), which discusses physiological jumping performance in cats, is mistakenly cited for the information that is instead contained in the papers by  Zajac (1985) and English (1987): English, A. W. 1987. An anatomical and functional analysis of cat biceps femoris and semitendinosus muscles. Journal of Morphology 191:161–175; Zajac, F. E. 1985. Thigh muscle activity during maximum-height jumps by cats. Journal of Neurophysiology 53:979–994.

  • On p. 446, I misspelled Megaconus as “Megaconodon.”

  • On p. 459, I say, “In opossums and other metatherians that lack a pouch …” which implies that all opossums lack a pouch. Although some metatherians (marsupials), including Monodelphis (the domestic or laboratory opossum) do indeed lack a pouch, most opossums have a pouch (marsupium).

  • On p.460 I state, “… approximately 2 Ma, the land bridge that now connects North and South America formed …” The land bridge formed closer to 3 Ma, and more recent data suggests an even earlier connection prior to 4 Ma.