All Yesterdays: Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals

by John Conway

  irregularbooks.co

  Acknowledgements

  We are thankful to our families and friends, whose love and support helped us through the making of this book. Several of our colleagues have provided feedback and discussion that helped shape our ideas. In particular Mike Taylor and Matt Wedel were generous with their encouragement and discussion.

  We thank the late Dan Varner for discussion on the history of palaeoart; and Tim Isles, Luis Rey, Mark Witton and Steve White for thoughts on palaeobiology and palaeoart.

  We thank John's wife, Jenny, for her support and proof-reading.

  C. M. Kosemen would like to extend special thanks towards his parents, brother and sister for their unconditional love, support and friendship.

  About the Authors

  John Conway

  Artist & Author

  John Conway is a palaeontological and fine artist, who's work has been used for National Geographic, Discovery Channel and the American Museum of Natural History, among others. His work has most recently appeared in Dinosaur Art: the World's Greatest Paleoart. John's interest in the methodology and culture of reconstructing of palaeontological subjects is the genesis of this book.

  Website: johnconway.co

  Twitter: @nyctopterus

  Facebook: facebook.com/nyctopterus

  C.M. Kosemen

  Artist & Author

  C. M. Kosemen holds a Media and Communications Masters' degree from Goldsmiths College, and has worked as an editor in Benetton Company's Colors magazine. He has had several exhibitons of his evolution-themed fine art at galleries and science festivals internationally. Kosemen's areas of specialization are speculative & real zoology, history and unusual things in general. His previous work includes Snaiad, a self-initiated web project about life on an alien planet.

  Website: www.cmkosemen.com

  Facebook: facebook.com/memo.kosemen

  Darren Naish

  Author

  Darren Naish is a science writer, technical editor and palaeozoologist. Darren works mostly on theropod and sauropods dinosaurs, but also works on pterosaurs, marine reptiles, and other tetrapods. With colleagues, he named the dinosaurs Eotyrannus, Mirischia and Xenoposeidon. Darren has written several books, including Walking With Dinosaurs: The Evidence (co-authored with David M. Martill), Great Dinosaur Discoveries, and more recently Tetrapod Zoology Book One. His blog, Tetrapod Zoology, is widely considered the world's foremost zoology blog.

  When not writing about tetrapods, Darren can be found pursuing his interest in modern wildlife and conservation and its resulting adventures in lizard-chasing, bird-watching and litter-collecting.

  Website: blogs.scientificamerican.com/tetrapod-zoology/

  Twitter: @TetZoo

  Scott Hartman

  Illustrator

  Scott Hartman is a palaeontologist and illustrator who specialises in creating skeletal diagrams of dinosaurs and other animals to the highest degree of scientific accuracy. Scott's skeletal drawings form the basis of many other artist's work.

  Website: skeletaldrawing.com

  Twitter: @skeletaldrawing

  Dedicated to Dan Varner

  All Yesterdays

  Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals

  By John Conway, C. M. Kosemen and Darren Naish with skeletal reconstructions by Scott Hartman

  Introduction, by Darren Naish

  A desire to imagine the long-extinct organisms of the past as living, moving animals has long inspired artists and scientists to clothe bones and other fossil tissues in muscles, skin, fur and feathers. In other words, to bring fossil animals 'back to life' in art. We need to be clear from the start that-while there are many things that we're surely getting right-there are many other things that have to be regarded as 'known unknowns', and even as 'unknown unknowns'. It is these areas of doubt and speculation that form the focus of this book, the first ever devoted entirely to the more speculative aspects of palaeoart.1

  It is well known that the process of reconstructing a fossil animal involves a marriage of both ‘hard’ data as well as a degree of informed speculation. That ‘hard’ data involves such things as the lengths and widths of bones and other hard parts, and the positions of specific muscle groups present in living animals. While the creation of a bone-and-muscles-only reconstruction should be seen as the first step in the depiction of a fossil animal (and even as a presumably inescapable part of creating a reconstruction!), readers may be surprised to learn that many people who have reconstructed extinct animals have frequently done so without recourse to these vital steps.

  We in fact know that this was true of some of the greatest and most influential palaeoartists of all time. The Czech master of ancient animals and landscapes Zdenîk Burian (1905-1981), for example, best-guessed the life appearance of dinosaurs and other vertebrates by fleshing out museum-mounted skeleton on paper without the use of measurements. Rudolph F. Zallinger’s (1919-1995) animals – most famously depicted in the Zallinger mural at Yale’s Peabody Museum of Natural History – were clearly done with only a superficial reference to the skeletons of the species concerned. The pieces of art generated by these individuals remain brilliant, beautiful and wonderful, but the techniques they used were damaging to the contention that the reconstruction of fossil animals involves science as much as it does art. Indeed, this concept is reflected in the paraphrased claim “There’s more than one way to reconstruct a dinosaur”, and in the general idea that dinosaurs and other fossil animals can only be reconstructed approximately, or with substantial doubt about the most basic issues remaining.

  So we must note to begin with that reconstructing a fossil animal is not a speculative process that has many possible outcomes, but a rigorous and evidence-led one where informed artists produce a technically accurate musculoskeletal reconstruction for a given animal. The problem comes with the integument – the covering that involves the skin and all the things attached to it (scales, feathers, hairs and so on) – as we'll see.

  Most people interested in palaeoart are aware of, and follow, the high-fidelity musculoskeletal reconstructions produced by researcher and artist Greg Paul. Many of Paul's hypotheses and arguments about archosaur2 biology and evolution are the topic of argument and disagreement, but his explanations and illustrations of archosaur anatomy and the way he restores an animal's musculoskeletal system remain important. Paul's 1987 article 'The science and art of restoring the life appearance of dinosaurs and their relatives: a rigorous how-to guide'3 remains a classic, and (while now very dated) it is probably the best and most useful introduction to the sort of information an artist would need (though read on).

  Paul's initial forays into the accurate reconstruction of archosaur musculature were the result of communication with Robert Bakker; in turn, both Paul and Bakker were inspired by Charles R. Knight's (1874-1953) discussions and depictions of animal anatomy. Knight is most famous for his many paintings of fossil dinosaurs and mammals, but he also illustrated living animals. His book—Animal Drawing: Anatomy and Action for Artists—should be obtained by anyone seriously interested in the subject.4 Therein, we see Knight's excellent attention to anatomical detail (especially in mammals), his knowledge of musculature, and his pioneering use of silhouetted outlines to show the extent of soft tissues around the skeleton. Here is the origin of the 'anatomically rigorous' movement in palaeoart. However, Knigh
t was a paradox. He understood well the link between osteology and musculature, yet he gave dinosaurs small, slender muscles that did not match their bones (dinosaurs actually seem to have had enormous, more bird-like muscles), and frequently drew dinosaurs freehand-style, again with what looks like poor attention to the proportions and nuances of the actual skeletons.

  Allosaurus (left) and Diplodocus (right) by Charles Knight. Note the slender, lizard-like thighs.

  This paradox - this inherent contradiction - has remained throughout the history of palaeoart. Yes, there are efforts to be as rigorous as possible and to put in an enormous amount of unseen background research on the detailed anatomy of those fossil animals being reconstructed, but there are also quick and dirty ways of doing things where research is minimal. A large number of popular books about prehistoric animals use the work of individuals who do no research whatsoever, creating their digitally reconstructed animals simply by copying those depicted beforehand by other artists.

  Paul's massive influence means that Mesozoic archosaurs-dinosaurs and pterosaurs especially-are nowadays frequently depicted in high-fidelity skeletal form before, or at the same time as, fleshed-out life reconstructions appear. Outside of archosaurs, little similar work is so obvious, bar the several anatomist-artists (including Jay Matternes and Adrie and Alfons Kennis) who have worked so hard to reconstruct the faces and bodies of fossil hominids. Mauricio Antón is now well known as an excellent and anatomically rigorous restorer of fossil mammals and other vertebrates: his books and technical articles are as much about the detailed science of anatomical reconstruction as they are about evolution and palaeobiology.5,6,7,8

  What needs to be made clear at this point, then, is that palaeoart of the sort discussed and depicted in this book is firmly grounded in a sceptical, rigorous, evidence-led effort to study and depict anatomy: the approach promoted by Paul, Antón and the like. Several other palaeoartists of the modern era-Jason Brougham, Mark Hallett, Scott Hartman, Bob Nicholls, Emily Willoughby and Mark Witton come to mind-are similarly part of the 'anatomically rigorous' movement. Others are not, and it shows.

  It should be noted that there are some disagreements at the level of reconstructing skeletons and musculature, and that improvements and tweaks are frequently being made. We mostly agree on the positions of muscles, for example, but the sizes of some of the muscles involved are variable in living animals and there is sometimes no reliable way of determining their size in fossil animals. This is well illustrated by Hutchinson et al.'s discussion of muscle mass and body size in Tyrannosaurus rex9 where competing possibilities made the same T. rex specimens look either svelte, muscular or ridiculously muscular. The forelimb posture of bipedal dinosaurs has been extensively revised in recent years as workers have shown that palms faced inwards, not downwards,10,11,12 and reassessment of dinosaurian tails have made it clear that Paul's dinosaurs are typically not bulky enough in the tail region.13

  Recent evidence suggests that dinosaurs were far more muscular in the tail region than previously assumed. This reconstruction of Tyrannosaurus rex, produced by Scott Hartman, has an appropriately chunky tail.

  The problem with integument

  The real complication in reconstructing fossil animals – the reason we’re here, with a published book on the subject – is that there’s all the soft stuff that goes on top of the musculoskeletal system. Integument is the great unknown for many fossil animals; its preservation is rare and infrequent, and even when it’s preserved, it may be massively distorted or rearranged relative to its position in life. This is important, since the shape and size of the integument can radically change the appearance of the living animal relative to its underlying musculature and skeleton. The skeletons of modern birds – owls and parrots, for example – have long, slender neck skeletons, but overlying skin and thick feather coverings obscure these entirely. Extravagant head, wing and tail feathers present in some birds are not reflected in the underlying osteology either, and the manes, ruffs, thick furry coats and extensive amounts of skin linking the body with the limbs in many modern mammals are, similarly, not suggested at all by osteology.

  If these observations extend across a wide diversity of living animals, would they have done so for extinct ones as well? We have little to go on, but what we know suggests that, yes, integumentary coverings may have effectively obscured much of the underlying anatomy that we’ve worked so hard to reconstruct. Notably, dinosaurs found with soft tissues (namely skin impressions and feathers) are flamboyant. Feathered dinosaurs are not only covered in feathers (with feathering extending from the middle of the snout all the way to the tip of the tail and even down to the ankles or toes), they have especially long, showy feathers growing off their arms and hands, the end parts of their tails, and even (in cases) from their thighs, shins and feet. Fossil mammals with body outlines and fur show a thick halo of tissues surrounding the skeleton, meaning that the skeleton was deeply submerged and effectively invisible in the live animal, as is typically the case in modern species.

  We are therefore presented with a huge diversity of ‘known unknowns’ and ‘unknown unknowns’ – the gate is open for all manner of bizarre possibilities as goes the life appearances of fossil animals.

  It is these speculative possibilities that John Conway and C. M. Kosemen have explored in this book. Palaeontologists and palaeoartists talk about these sorts of ideas all the time-about the possibility that extinct animals were insanely flamboyant, that they had super-sized genitalia, or that they were insulated from the cool or even cold environments they sometimes inhabited by fat, thick skin, or fuzzy coats-but this is the first time ideas of this sort have been extensively discussed in print.

  John Conway and C. M. Kosemen are two of the most exciting of modern artists who are depicting extinct animals. Both combine remarkable attention to detail and technical accuracy with an understanding of art and art history and a desire to move forwards-to do something new, something innovative. Notably, both produce work in the digital realm and the internet is the true home of their many creations. A selection of John's outstanding works has recently been showcased in the stunning Dinosaur Art volume14 and he is rapidly becoming well known as the face of the future. His dinosaurs and pterosaurs are not garish, flamboyantly pigmented, or shown in a stereotypical landscape of palm trees and volcanoes, but realistically muted and subtly hued, fitting into backgrounds that have been compared by some to impressionist paintings or Chinese watercolours. C. M. Kosemen is best known for his remarkable speculative and 'alternative' animals, some created as inhabitants of speculative future evolutionary scenarios (see his All Tomorrows project, available for free online, on human evolution) or of other planets (see his Snaiad project). His speculative 'smart dinosaur'- later labelled Avisapiens saurotheos and created as an antidote to the green, scaly humanoids imagined by some palaeontologists-became an internet sensation.

  Above, Two aliens, a predatory Kahydron >and an armored, herbivorous Allotaur, from C. M. Kosemen's Snaiad. Below, the intelligent Avisapiens, also by C. M. Kosemen.

  To the future!

  This book goes beyond some speculative possibilities about the life of the past; it also indulges in a fun thought-experiment about a hypothetical future. We humans have struggled to interpret the often scrappy remains of fossil reptiles and other animals – it has taken us decades, and a huge amount of luck and careful detective work, to understand the true life appearance of small, predatory dinosaurs, giant marine reptiles like plesiosaurs and mosasaurs, and other such creatures. Think of the many mistakes we made along the way: plesiosaurs with the insanely long neck misinterpreted as the tail, Iguanodon imagined as a rhino-shaped, reptilian ‘pachyderm’, bird-like predatory dinosaurs depicted more as big lizards or even as giant turtles (this happened with Therizinosaurus), and so on.

  Now consider what might happen were hypothetical non-human scientists confronted with the remains of modern animals.
If we imagine that these curious and scientifically advanced creatures tried to reconstruct modern birds, mammals and other animals, would they end up with reconstructions that approach reality? It’s an interesting thought experiment. Indeed, I tried it myself some years ago, wondering just how modern cetaceans might be reconstructed if hypothetical future scientists looked at them without knowing of mammalian soft tissues. Many cetaceans have bizarre tall spines growing upwards from their vertebrae; such distinctive structures as the fatty melon on the top of the head and tail flukes are wholly missing in fossils, and there’s no clear evidence for a thick covering of blubber. Here, then, are my 1997 efforts to imagine a bottlenose dolphin and Dall’s porpoise, pretending all the while that I’m a non-human, non-mammalian palaeontologist from the future…

  However, certain characteristics known as osteological correlates 15 can be used, with some reliability, to deduce soft tissue or integument from skeletal details. Trunked mammals like elephants have unusual bony recesses and other structures around their enlarged bony nasal openings that help anchor the musculature associated with a proboscis, and also possess a specially enlarged braincase opening for one of the nerves that supplies the trunk. The melons and spermaceti organs of toothed whales are housed in concave basins on the skull roof, and the presence of horizontal tail flukes in cetaceans are hinted at by the shapes of the vertebrae at the tail’s end. However, these are things that we’ve discovered with the benefit of hindsight, or have investigated specifically because we knew about the soft tissue structures in the first place. If we truly imagine that modern animals are represented in a future fossil record by imperfect remains, just like ancient fossils in the real, modern-day world, things could indeed be very different.