Dinosaurs Without Bones (57 page)

p. 47
   “At one site in Middle Jurassic (about 165 mya) rocks of Zimbabwe, trackways of at least five large theropods … were traveling together.” Lingham-Solier, T., Broderick, T., and Ahmed, A.A.K. 2003. Closely associated theropod tracks from the Jurassic of Zimbabwe. Naturwissenschaften, 90: 572-576.

p. 47
   “An Early Cretaceous (about 125 mya) site in China also shows six theropod trackways, equally spaced and pointing in the same direction… .” Li, R., Lockley, M.G., Makovicky, P.J., Matsukawa, M., Norell, M.A., Harris, J.D., and Liu, M. 2008. Behavioral and faunal implications of Early Cretaceous deinonychosaur trackways from China. Naturwissenschaften, 95: 185-191.

p. 48
    “This trackway, discovered by paleontologist Roland Bird in 1938, was in a limestone bed cropping out in the Paluxy River.” Bird, R.T. 1985. Bones for Barnum Brown: Adventures of a Dinosaur Hunter. Texas Christian University Press, Ft. Worth, Texas: 225 p.

p. 49
   “So now the more reasonable explanation is that, yes, the theropod might have been stalking the sauropod but did not jump onto it there.” Farlow, J.O., O’Brien, M.O., Kuban, G.J., Datillo, B.F., Bates, K.T., Falkingham, P.L., Piñuela, L., Rose, A., Freels, A., Kumagi, C., Libben, C., Smith, J., and Whitcraft, J. 2012. Dinosaur tracksites of the Paluxy River Valley (Glen Rose Formation, Lower Cretaceous), Dinosaur Valley State Park, Somervell County, Texas. Actas de V Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, Salas de los Infantes, Burgos: 41-69.

p. 49
   “Glen Kuban, a paleontologist who has studied and mapped the Paluxy River dinosaur tracks for more than twenty years… .” Kuban, G. 1989. Elongate dinosaur tracks. In Gillette, D.D., and Lockley, M.G. (editors), Dinosaur Tracks and Traces. Cambridge University Press, Cambridge, U.K.: 57-72.

p. 50
   “Researchers who worked on this site had also found sauropod tracks, showing they also lived in the area, but found ominous toothmarks on the bones along with shed teeth of juvenile and adult Allosaurus.” Jennings, D.S., and Hasiotis, S.T. 2006. Taphonomic analysis of a dinosaur feeding site using geographic information systems (GIS), Morrison Formation, southern Bighorn Basin, Wyoming, USA. Palaios, 21: 480-492.

p. 51
   “In a 2009 journal article with the beguiling title of ‘Dinosaur Death Pits from the Jurassic of China’… .” Eberth, D.A., Xing, X., and Clark, J.M. 2009. Dinosaur death pits from the Jurassic of China. Palaios, 25: 112-125.

p. 52
   “Sure enough, a few fossils, such as snails and clams, found in dinosaur tracks were crushed underfoot… .” In the Morrison Formation of Colorado—at the same tracksite with herding sauropods—Lockley et al. (1986) found crushed clams in sauropod footprints and interpreted this as the sauropods having “killed” them. But I’ve also stepped on and crushed many clams that were dead long before I got there. Hence I’m a little skeptical that sauropods were responsible for their deaths: this could have been post-mortem smashing. Similarly, I’ve seen snail shells in Late Jurassic sauropod tracks in Switzerland, and again can’t say for sure whether they were dead or alive when these dinosaurs put their feet down on them.

p. 52
   “One theropod trackway in the Late Jurassic in Utah leaves no doubt that its maker had a tough time walking… .” Lockley, M.G., Hunt, A.P., Moratalla, J.J., and Matsukawa, M. 1994. Limping dinosaurs? trackway evidence for abnormal gaits. Ichnos, 3: 193-202.

p. 53
    “One such trackway is from the Early Jurassic of Massachusetts, in which three tracks in sequence—right, left, right—have a perfectly fine three-toed theropod track on the left, but a two-toed one on the right, missing its innermost digit.” Lockley (1991).

p. 54
   “It also left lots of other evidence for its impact, not least of which is a huge crater of the right size and age in the Gulf of Mexico next to the Yucatan peninsula of Mexico.” The original article that started the “meteorite killed the dinosaurs” hypothesis was: Alvarez, L.W., Alvarez, W., Asaro, F., and Michel, H.V. 1980. Extraterrestrial cause for the Cretaceous-Tertiary extinction. Science, 208: 1095-1108. (2) A good book written for a lay audience that summarizes the scientific story of the hypothesis, and written by one of the discoverers of the evidence for the meteorite impact is: Alvarez, W. 2008. T. rex and the Crater of Doom. Princeton University Press, Princeton, New Jersey: 216 p.

p. 55
   “One such site in Utah has hundreds of deeply impressed tracks preserved in strata at multiple levels, one of which is only a few meters below the boundary.” Dilfey, R.L., and Ekdale, A.A. 2002. Footprints of Utah’s last dinosaurs: track beds in the Upper Cretaceous (Maastrichtian) North Horn Formation of the Wasatch Plateau, central Utah. Palaios, 17: 327-346.

p. 55
   “A single—but huge—theropod track from New Mexico, attributed to Tyrannosaurus rex, also came from a layer just below the boundary.” Lockley, M.G., and Hunt, A.P. 1994. A track of the giant theropod dinosaur Tyrannosaurus from close to the Cretaceous/Tertiary Boundary, northern New Mexico. Ichnos, 3: 213-218.

p. 55
   “In Spain, abundant dinosaur tracks, some ascribed to hadrosaurs and sauropods, are preserved only a few meters below strata that preserved fossils of Paleogene fish and mammals.” Riera, V., Oms, O., Gaete, R., and Galobart, A. 2009. The end-Cretaceous dinosaur succession in Europe: the Tremp Basin record (Spain). Palaeogeography, Palaeoclimatology, Palaeoecology, 283: 160-171.

p. 55
   “At one site, more than forty horizons contained hadrosaur and sauropod tracks below the boundary, and paleontologists estimated that some tracks were made only 300,000 years before the end of the Cretaceous.” Villa, B., Oms, O., Fondevilla, V., Gaete, R., Galobart, A., and Riera, V. 2013. The latest succession of dinosaur tracksites in Europe: hadrosaur ichnology, track production and paleoenvironments. PLoS One, 8: e72579. doi:10.1371/journal.pone.0072579

CHAPTER 3: THEY MYSTERY OF LARK QUARRY

p. 61
   “As is still typical for fossil finds in many parts of the world, it was spotted by a sharp-eyed amateur, cattle station manager Glen Seymour, who lived and worked in the area.” The best historical account
I’ve read about the discovery and uncovering of the Lark Quarry tracksite was in the annual magazine of the Australian Age of Dinosaurs (Winton, Australia): Meiklejohn, D., and Elliott, J. 2004. The ghosts of Lark Quarry. Australian Age of Dinosaurs, Issue 2: 18-31.

p. 61
   “Otherwise, nothing much in a scientific sort of way happened until 1971, when Mr. McKenzie and Mr. Knowles took paleontologists to the site… .” Although this part of the story is again related in Meiklejohn’s (2004) Australian Age of Dinosaurs article, the part where Pat Vickers-Rich and Tom Rich accompanied the others to the site was told to me personally by none other than Pat Vickers-Rich and Tom Rich.

p. 63
   “Based on Thulborn and Wade’s analysis of the site, the area was a lakeshore that had been submerged regularly by a nearby stream emptying into it.” (1) Thulborn, and Wade. (1979).

p. 64
   “Persuasive circumstantial evidence leads us to conclude that they represent a stampede—that is, a wild, unreasoning and panic-stricken rush to escape the threat of danger. What could have caused such presumed panic?” Thulborn and Wade (1979).

p. 65
   “The second, published in 1984, was a much longer and more detailed report modestly titled ‘Dinosaur Trackways in the Winton Formation (Mid-Cretaceous) of Queensland.’” Thulborn, R.A., and Wade, M. 1984. Dinosaur trackways in the Winton Formation (mid-Cretaceous) of Queensland. Memoirs Queensland Museum, 21: 413-517.

p. 67
   “The fresh hypothesis states that the ‘dinosaur stampede’ was not triggered by the arrival of a predator, and no stalking of other dinosaurs by a voracious predator happened either.” Romilio, A., and Salisbury, S.W. 2011. A reassessment of large theropod dinosaur tracks from the mid-Cretaceous (late Albian–Cenomanian) Winton Formation of Lark Quarry, central-western Queensland, Australia: a case for mistaken identity. Cretaceous Research, 32: 135-142.

p. 69
   “After all, hypotheses are only accepted conditionally, and then are subject to further testing so we can find out whether or not they still hold up to scrutiny.” Cleland, C.E. 2001. Historical science, experimental science, and the scientific method. Geology, 29: 987-990.

p. 70
   “Why identifying the maker of these big tracks is so difficult is mostly attributable to the tracks only having three toes, a trait also known as tridactyl.” Farlow et al. (2012).

p. 70
   “On average, theropod tracks are longer than they are wide, whereas ornithopod tracks are wider than they are long.” (1) Lockley (2009); (2) Farlow et al. (2012).

p. 71
   “In an article published in 1988, they used a sample of 66 Early Cretaceous tridactyl dinosaur tracks from Spain, all of which had been identified confidently as either ornithopod or theropod tracks on the
basis of their qualities.” Moratalla, J.J., Sanz., S.L., and Jimenez, S. 1988. Multivariate analysis on Lower Cretaceous dinosaur footprints: discrimination between ornithopods and theropods. Geobios, 21: 395-408.

p. 73
   “Skeletal remains of this ornithopod were discovered in 1963 near the small town of Muttaburra in central Queensland, northeast of Lark Quarry… .” Bartholomai, A., and Molnar, R.E. 1981. Muttaburrasaurus: a new Iguanodontid (Ornithischia:Ornithopoda) dinosaur from the Lower Cretaceous of Queensland. Memoirs of the Queensland Museum, 20: 319-349.

p. 73
   “In contrast, bones of only one large predatory theropod … Australovenator wintonensis, lovingly nicknamed ‘Banjo’… .” Hocknull, S.A., White, M.A., Tischler, T. R., Cook, A.G., Calleja, N.D., Sloan, T., and Elliott, D. A. 2009. New mid-Cretaceous (Latest Albian) dinosaurs from Winton, Queensland, Australia. PLoS One, 4: e6190.

p. 74
   “Interestingly, objections to this identification, voiced formally by Romilio and Salisbury, were not new, as a few dinosaur paleontologists questioned it soon after Thulborn and Wade’s second article came out in 1984.” (1) Paul, G. 1988. Predatory Dinosaurs of the World. Simon and Shuster, New York: 464 p. (2) Lockley and Hunt (1994).

p. 74
     “I say the last facetiously, but a small troupe of creative folks actually did write and perform a short musical number retelling the original story of the dinosaur stampede… .” The performance was recorded, placed on YouTube on September 29, 2012, and is titled Dinosaur Stampede MASA2012: http://www.youtube.com/ watch?v=midGaNNHhbM

p. 77
     “In this manuscript, which was posted online in the same journal (Cretaceous Research) that published the re-study… .” The article was initially available online November 22, 2011, then withdrawn sometime before May 2012. Apparently, the author was never notified by the journal of the withdrawal, and learned about its disappearance from others. The link to the former article and the “Withdrawn” notice are here: http://www.sciencedirect.com/science/article/pii/S0195667111001844

p. 78
     “Hence, it did what very few academic journals do, which was pull the article offline.” As part of an online scientific community, I recall the surprise and discussion that took place among paleontologists after this happened, with much speculation about why it was justified. Some of this is summarized by Brian Switek, along with his coverage of the new interpretation of the “stampede” track-site as a “swimsite,” here: http://phenomena.nationalgeographic.com/2013/01/11/swim-tracks-undermine-dinosaur-stampede/

p. 79
   “Thulborn submitted a revised version of his article to the Australian
Thulborn, R.A. (2013): Lark Quarry revisited: a critique of methods used to identify a large dinosaurian track-maker in the Winton Formation (Albian–Cenomanian), western Queensland, Australia.
Alcheringa: An Australasian Journal of Palaeontology
, doi:10.1080/03115518.20 13.748482

p. 79
   “Then, also early in 2013, the aquamusical version was unveiled.” Romilio, A., Tucker, R., and Salisbury, S.W. 2013. Reevaluation of the Lake Quarry dinosaur tracksite (late Albian-Cenomanian Winton Formation, central-western Queensland, Australia): no longer a stampede?
Journal of Vertebrate Paleontology
, 33: 102-120.

p. 80
    “Just how did I get trapped in the building housing these fabled and controversial dinosaur tracks?” Much of this story I told before in an invited article for
Australian Age of Dinosaurs
magazine (2011 issue), written as a humorous end piece to the magazine (called the “Tail Bone”) and titled
Sleeping with the Dinosaur Tracks
.

CHAPTER 4: DINOSAUR NESTS AND BRINGING UP BABIES

p. 86
   “How did male dinosaurs get past the thick tails of some females to reach their goals? More intriguing, how did male dinosaurs get past the spiky or clubbed tails of some females?” Brian Switek, in his book
My Beloved Brontosaurus
(2013, Farrar, Straus, and Giroux, 256 p.), explores the intriguing topic of dinosaur sex with great humor and deeply penetrating prose in a chapter titled “The Big Bang Theory.” In this chapter, he discusses the pros and cons of dinosaur positions, so with those in mind, it is even more fun to imagine the traces these would have made.

p. 87
   “This discovery was of a small ceratopsian dinosaur,
Protoceratops
, on top of a dromaeosaur,
Velociraptor
, with both locked in an embrace but a pointedly deadly one.” Although this deservedly famous pair of fossils has been much discussed since its discovery in 1971, the first peer-reviewed publication reporting it was: Barsbold, R. 1974. Saurornithoididae, a new family of theropod dinosaurs from Central Asia and North America.
Paleontologica Polonica
, 30: 5-22.

p. 87
   “… but more emblematic of Tennyson’s ‘nature, red in tooth and claw.’” This famous phrase, with its allusions to Darwinian struggles (albeit ten years before publication of Darwin’s
On the Origin of Species
) comes from section (Canto) 56 of Alfred, Lord Tennyson’s epic poem,
In Memoriam A.H.H
., finished in 1849. This poem is explored in depth by a Stephen Jay Gould essay, “The Tooth and Claw Centennial,” in: Gould, S.J. 1995.
Dinosaur in a Haystack
. Harmony Books, New York: 63-75.