Microraptors © Gregory S. Paul The Prehistoric Times Interview: Gregory S. Paul ByVince 1.J. Curley Vince Curley: Your Book, Predatory Dinosaurs of the World is one of the greatest dinosaur hooks ever written. I've been told it's no longer in print, which I feel is a great injustice. Is this true, and if so, is there any possibility of another edition coming out again? Gregory S. Paul: Just one of the greatest dinosaur books ever written? But seriously, the book is too out of date to be in print. And, someday .... V.C.: The Scientific pieces at the Lambeosaurus © Gregory S. Paul American book of Dinosaurs Dinosaur National is a huge undertaking, with Monument. His excellent artwork and infor- snorkeling mative contributions from so Diplodocus ·pair is many good scientists. How the most evocative did this project come about; expression of the was it your brainchild or view of sauropods something Scientific as semi-aquatic American asked you to ever achieved. accomplish? Meanwhile the Allosaurus chas- GSP: The publisher of the ing Camptosaurus book was kind enough to ask would not look out me to be the editor. That is of place in a cur- not really a huge undertak- rent book on ing, since as editor I let oth- dinosaurs. It is a ers do most of the work. shame they are filed away rather V.C.: Whom would you list than be displayed as being your biggest influ- on tbe side some- ences in your dinosaur art, in -- ..:- __ ..::.c_.-" where. I was delighted to get inditermsvidualofs?past and present '"======================================~r them published in Camptosaurus & Dryosaurus © Gregory S. Paul the Sci Amer book. GSP: One of the biggest was I was influenced Charles Knight, of course (I by Burian, did an article on him for Zallinger and the Scientific American reprint- like as well, but to a ed in the Sci Amer book, lesser degree thereby reducing the work because their work load further). In terms of the was more free style art and mood, not the out-of- artistic than date morphological details. anatomically seri- Then there are the fantastic, ous. The same was hyper detailed Jay Matternes true on William Cenozoic murals at the Scheele in his two Smithsonian; I grew up just marvelous charcoal outside Washington DC. His illustrated books skeletal-muscle restorations from the 1950s, but were also influential. I love the art any- Additionally important were how. the little known, but exquis- V.C.: It seems you ite Bill Berry Morrison fauna ~------------------------------------------------------------~ 42 Prehistoric Times No. 75 Dec/Jan 2006 feel that the meteorite impact in the Yucatan Peninsula is perhaps supe- Gorgosaurus © Gregory S. Paul rior to other fundamental ideas regarding dinosaur extinction, yet is not the be all or end all. Are you a proponent of multi-factors which occurred to lead to the KT extinction? If so, what other factors can you extrapolate on and share with P.T. readers? V.c.: Getting more specific about dinosaur anatomy, why is the absence of chevrons under the tail of pachy- cephalosaurs so signif- icant? GSP: They are absent under the tail base. This simply means that the space available for a peculiar extension of the digestive tract to behind the pelvis had taken place. This pos- terior part of the diges- tive tract was support- ed by unusually broad transverse processes. /=======================================: The arrangement seems to have some- thing to do with Acrocanthosaurus © Gregory S. Paul increasing the ability of the digestive com- plex to process the plants they ate. v.c.. When restoring the life appearances of V.c.: What was it like ceratopsians, I've working' as a consultant noted that you equate to "Jurassic Park" and their musculature as Disney's "Dinosaur?" similar, but more mas- Any opinions on the sive, than extant B.B.C.'s "Walking with rhino's. Is it the sheer Dinosaurs" series? robust nature of their bones that steer you in GSP: I barely worked on this direction? What Prehistoric Times No. 75 Dec/Jan 2006 43 ornithischians, as well as therizinosaurs, probably had elastic cheeks that contained food as it was orally processed. The tooth rows were usually set close to one another, leaving limited space in the oral cavity, while the cheek pouches were quite deep. Looks like they were chomping up the plant parts into little pieces that fell into the cheek pouches, to be swept back into the mouth with a long, supple tonque, and rechomped until Brachiosaurus © Gregory S. Paul Hornalocephale Pachycephalosaurus (same scale) © Gregory S. Paul other features do you regard as unusual in ceratopsians? GSP: Ceratopsians were much more strongly built than rhi- nos in terms of bone robustness. Also, they had enormous pelvic girdles, and the limbs were longer than rhinos of equal mass. All this implies that ceratopsids had larger leg muscles than rhinos. This was probably to give the the abil- ity to fight off the enormous tyrannosaurids - of course Happ has just shown that Tyrannosaurus engaged in direct combat with Triceratops, one of the latter having healed bite marks on its skull. Rhinos do not have to contend with such super predators. v.c.: The debate on "cheeky" ornithischians seems to pop up a great deaL Jack Horner and Michael Brett-Surman say that without cheeks they would've' been very poor eaters. Some others feel that cheeks and other facial muscles are a purely mam- malian trait and don't belong on a reptilian or aves-like character. What i~ your ultimate stance on this, and have you seen any evidence of ligamenta- tion or other muscle tissue markings on fossilized skulls and jaws to permii the presence of cheeks? GSP: Condors have well developed elastic cheeks that shorten the lengths of their mouths. We know that ankylosaurs had cheeks that almost reached their beaks because they are actually ossified in some cases. Most ifnot all Edmontonia © Gregory S. Paul 44 they were ready to swallow. It is hard coming up with a way that ornithsichian mouths worked without cheeks. V.c.: What is your stance on the importance of Brachiosaurus, or Therizinosaurus having a pelvis rotated backward relative to the trunk vertebrae? How does this differ from most theropods and bipedal Ornithischians? GSP: As I explained in PDW, when most theropods reared up, the forward rotation of the pelvis threw things out of whack and it was not possible for them to move fast. Most therizinosaurs had retro- verted pelves because they always moved about with the trunk angled up about 45 degrees. The pelvis and tail remained horizon- tal and fully functional regardless of speed this way. In a number of sauropods, camarasaurs, mamenchisaurs, euhelopids, and bra- chiosaurs, the pelvis was retroverted. In most this arrangement does not make sense unless the animals were rearing up and slow- ly walking about on their hindlegs on a fairly regular basis, proba-I bly mainly to move about as they feed as high as possible. In bra- chiosaurs the trunk was always tilted strongly up because the arms l'liiiiiiiiiiiiii -- were so long. were you seeing earlier on that instinctually made you disagree with earlier V.C.: I've always pondered the •••....,-----:-:;.-1.,-. orthodox thinking regarding Centrt;isa, dinosaur illustrations and relatively extreme differences between dinosaur feet and interpretation? their hands, Any personal the- ories or hypothesis as to why GSP: Good old Knight kept there exists such differences? putting wee, narrow, lizard- croc like muscles on his GSP: Probably because the dinosaurs even though they group has a bipedal heritage. had large pelvic plates that In no group - not even in long clearly supported enormous necked sauropods and ceratop- leg muscles like modem birds sids - was the majority of body and mammals. Animals with mass borne by the arms high aerobic exercise scopes (unlike elephants and large have larger limb muscles than ungulates), and the hands reptiles. This always sort of never developed large pads bothered me when I was a kid like those found on the hind- and teen doing dinosaur pic- feet of 'a number of big tures, but I did not know quite dinosaurs. why. This problem disap- peared when the concept that V.C.: I find it very interesting that you regard Archaeopteryx as not only a dinosaurs were as aerobically energetic as birds and mammals came out in theropod, as opposed to an actual bird, but also likely Dromaeosaurid, the 70s. I immediately started putting large, broad thighs on all dinosaurs, Could you please enlighten and big drumsticks on the faster, flex legged forms with big knee crests. P.T. readers as to how and why Kritosaurus.© Gregory S. Paul . you came to this conclusion? V.c.: Do you have any new -- revelations to add to your GSP: Archaeopteryx was not unique hypothesis of sec- a Dromaeosaurid; that's a spe- ondary flightlessness? In other cific family. But, as many words, what new info has researchers agree, the two emerged to make you feel that groups are much more similar dromaeosaurs, troodontids, to one another than they are to oviraptorosaurs, etc., are not anything else. Basically, they dinosaur ancestors or cousins, share a similar over all mor- but actual birds who lost their phological grade, with ability to fly? Archaeopteryx being more avian in some ways, and dro- GSP: I covered that pretty maeosaurs in others. Sorting thoroughly in the article I did out the exact position of these for Prehistoric Times issue types relative to birds requires #60. No two ways about it, the more research, and more fossils of related dino-birds.