Dinosaurs Without Bones

by Anthony J. Martin

  p. 35 “The first discovered running-dinosaur trackways were from a site in Texas, where at least three theropods moved at high speed.” Farlow, J.O. 1981. Estimates of dinosaur speeds from a new trackway site in Texas. Nature, 294: 747-748.

  p. 35 “To put it into a bipedal-human perspective, the top speed recorded by Usain Bolt over 200 m (656 ft) during the 2012 Olympics was also 27 mph… .” Hernández-Gómez, J.J., Marquina, V., and Gómez, R.W. 2013. On the performance of Usain Bolt in the 100 m sprint. European Journal of Physics, 34: 1227.

  p. 35 “Theropods and humans alike, though, would be humbled by the top speed recorded by a cheetah (Acinonyx jubatus)… .” Sharp, N.C.C. 1997. Timed running speed of a cheetah (Acinonyx jubatus). Journal of Zoology, 241: 493-494.

  p. 35 “Nonetheless, a dinosaur tracksite in Queensland, Australia outdoes the Texas tracksite for sheer numbers of running dinosaurs.” This tracksite was first interpreted as a “dinosaur racetrack” by: Thulborn, R.A., and Wade, M. 1979. Dinosaur stampede in the Cretaceous of Queensland. Lethaia, 12: 275-279. However, it was also recently reinterpreted as a “dinosaur natatorium” (swimsite) by: 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. 36 “For example, the fastest bipedal land animals today are ostriches (Struthio camelus), which have maximum speeds of 45 mph (72 kph).” Mechanics of running of the ostrich (Struthio camelus). Journal of Zoology, 187: 169-178.

  p. 36 “One paleontologist, Jim Farlow, and two other colleagues figured out that given the average mass of an adult T. rex… .” Farlow, J.O., Smith, M.B., and Robinson, J.M. 1995. Body mass, bone “strength indication,” and cursorial potential of Tyrannosaurus rex. Journal of Vertebrate Paleontology, 15: 713-725.

  p. 37 “What they found was that a 45-mph-running T. rex would have required about 85% of its entire body mass concentrated in its legs… .” Hutchinson, J.R., and Garcia, M. 2002. Tyrannosaurus was not a fast runner. Nature, 415: 1018-1021.

  p. 37 “Both of these skeletons belong to the same species of dinosaur, Mei long (‘soundly sleeping dragon’).” (1) Xu, X., and Norell, M.A. 2004. A new troodontid dinosaur from China with avianlike sleeping posture. Nature, 431: 838-841. (2) Gao, C., Morschhauser, E.M., Varricchio, D.J., Liu, J., and Zhao, B. 2012. A second soundly sleeping dragon: new anatomical details of the Chinese troodontid Mei long with implications for phylogeny and taphonomy. PLoS One, 7: e45203, doi:10.1371/journal.pone.0045203.

  p. 38 “A few other dinosaur skeletons, such as those of the theropod Citipati, have been found preserved in sitting positions… .” (1) Norell, M.A., Clark, J.M., Chiappe, L.M., and Dashzeveg, D. 1995. A nesting dinosaur. Nature, 378: 774-776. (2) Varricchio et al. (1997).

  p. 39 “Incidentally, dinosaur tail impressions are quite rare, with fewer than forty reported from the entire geologic record… .” Kim, J.Y., and Lockley, M.G. 2013. Review of dinosaur tail traces. Ichnos, 20: 129-141.

  p. 39 “Reported in 2009 in southwestern Utah, this Early Jurassic trace fossil not only shows where a theropod approached a sitting spot and sat down… .” Milner, A.R.C., Harris, J.D., Lockley, M.G., Kirkland, J.I., and Matthews, N.A. 2009. Bird-like anatomy, posture, and behavior revealed by an Early Jurassic theropod dinosaur resting trace. PLoS One, 4: e4591. doi:4510.1371/journal.pone.0004591.

  p. 40 “We were also testing an audacious claim that some of the wrinkle marks near the edge of the leg impressions were actually from feathers.” Martin, A.J., and Rainforth, E.M. 2004. A theropod resting trace that is also a locomotion trace: case study of Hitchcock’s specimen AC 1/7. Geological Society of America Abstracts with Programs 36(2): 96.

  p. 41 “In short, this specimen records a full sequence of movement by the theropod and how it altered the ground beneath it… .” Martin and Rainforth (2004).

  p. 42 “Only later did paleontologists realize this ‘webbing’ was actually a result of skin drying around its bones after the dinosaur had died.” Manning, P. 2008. Grave Secrets of Dinosaurs: Soft Tissues and Hard Science. National Geographic Society, Washington, D.C.: 316 p.

  p. 42 “A major flaw in this seemingly marvelous adaptation was that the hollow tube in the center of the crest, once studied in more detail later… .” Weishampel, D.B. 1981. The nasal cavity of lambeosaurine hadrosaurids (Reptilia:Ornithischia): comparative anatomy and homologies. Journal of Paleontology, 55: 1046-1057.

  p. 42 “Once he investigated, he … made an astonishing discovery: the first known sauropod dinosaur tracks from the geologic record.” Bird, R.T. 1985. Bones for Barnum Brown: Adventures of a Dinosaur Hunter. Texas Christian University Press, Ft. Worth, Texas: 225 p.

  p. 43 “Later, a closer look at these tracks showed that the missing tracks in the sequence of steps could be attributed to differences in track preservation.” Lockley, M.G., and Rice, A. 1990. Did Brontosaurus ever swim out to sea? Ichnos, 1: 81-90.

  p. 43 “These tracks are also in rocks from near the start of sauropods in the fossil record (Late Triassic) to their very end (Late Cretaceous).” Lockley et al. (2001).

  p. 43 “Yet Indian elephants (Elephas maximus) can swim as far as 25 miles (40 km), a feat far better than most humans are capable of.” Johnson, D.E. 1980. Problems in the land vertebrate zoogeography of certain islands and the swimming power of elephants. Journal of Biogeography, 7: 383-398. However, on September 2, 2013, Diana Nyad successfully completed swimming 178 km (110 mi) from Cuba to Florida, a distance that would be the envy of all water-crossing elephants.

  p. 44 “In fact, elephant swimming abilities show one of the probable ways mammoths dispersed to islands during the Pleistocene Epoch, where some isolated populations lasted until only about 4,000 years ago.” (1) Vartanyan, S.L., Garutt, V.E., and Sher, A.V. 1993. Holocene dwarf mammoths from Wrangel Island in the Siberian Arctic. Nature, 362: 337-340. (2) Johnson (1980).

  p. 44 “First, as early as 1980, a paleontologist interpreted swim tracks from Early Jurassic rocks of Connecticut as made by theropods… .” Coombs, W.P., Jr. 1980. Swimming ability of carnivorous dinosaurs. Science, 207: 1198-1200.

  p. 44 “… in 2001, paleontologists working in separate studies and places (Wyoming and the U.K.) interpreted Middle Jurassic tracks as possible dinosaur swim tracks.” (1) Kvale, E.P., Johnson, G.D., Mickelson, D.L., Keller, K., Furer, L.C., and Archer, A.W. 2001. Middle Jurassic (Bajocian and Bathonian) dinosaur megatracksites, Bighorn Basin, Wyoming, U.S.A. Palaios, 16: 233-254. (2) Whyte, M.A., and Romano, M. 2001. A dinosaur ichonocoenoses from the Middle Jurassic of Yorkshire, UK. Ichnos, 8: 223-234.

  p. 44 “Soon after that (2006), hundreds of much better examples were discovered and documented by Andrew Milner in Early Jurassic rocks of southwestern Utah… .” Milner, A.R.C., Lockley, M.R., and Kirkland, J.I. 2006. A large collection of well-preserved theropod dinosaur swim tracks from the Moenave Formation, St. George, Utah. In Harris, J.D., et al. (editors), The Triassic-Jurassic Terrestrial Transition. New Mexico Museum of Natural History and Science Bulletin, 37: 315-328.

  p. 44 “The next year (2007), dinosaur swim tracks were again interpreted from long linear marks on an expansive surface of Early Cretaceous rock in Spain.” Ezquerra, R., Doublet, S., Costeur, L., Galton, P.M., and Pérez-Lorente, F. 2007. Were non-avian theropod dinosaurs able to swim? supportive evidence from an Early Cretaceous trackway, Cameros Basin (La Rioja, Spain). Geology, 35: 507-510.

  p. 44 “In 2013, yet more dinosaur swim tracks were reported from another Early Cretaceous site in Queensland, Australia.” Romilio et al. (2013), and the controversy over this reinterpretation of what was regarded as a “dinosaur stampede” site is taken up in Chapter 3. Also in 2013, yet another example of dinosaur swim tracks was interpreted from China: Xing, L.D., Lockley, M.G., Zhang, J.O., Milner, A.R.C., Klein, H., Li, D.Q., Persons, W.S., and Ebi, J.F. 2013. A new Early Cretaceous dinosaur track a
ssemblage and the first definite non-avian theropod swim trackway from China. Chinese Science Bulletin, 58: 2370-2378.

  p. 45 “Not surprisingly, recreational purposes have never been suggested for swimming dinosaurs, but who knows whether an occasional dip might have also relieved any dinosaurs suffering from skin parasites or a hot day in the Mesozoic.” While hiking by a lake in the Piedmont National Wildlife Refuge in mid-Georgia on a summer day, I was shocked to see a deer swimming vigorously around the lake edge. At some point it came up on the bank, and when I trained my binoculars on it, I could see its body was covered with hundreds of ticks. So it must have been desperate to either get rid of them or to at least feel better. I felt terrible for the deer, but also made a mental note that this was yet another reason why animals that don’t normally swim would get into the water.

  p. 46 “This site has trackways of more than twenty sauropods walking in the same direction and apparently made at about the same time.” Castanera, D., Barco, J., Díaz-Martínez, I., Gascón, J., Pérez-Lorente, F., and Canudo, J. 2011. New evidence of a herd of titanosauriform sauropods from the Lower Berriasian of the Iberian Range (Spain). Palaeogeography, Palaeoclimatology, Palaeoecology, 310: 227-237.

  p. 46 “A Late Jurassic sauropod tracksite near La Junta, Colorado, also shows the tracks of five sauropods moving in the same direction, Price, N.K. 1986. North America’s largest dinosaur trackway site: implications for Morrison Formation paleoecology. Geological Society of America Bulletin, 97: 1163-1176. (2) Lockley (1991).

  p. 47 “The tracksite in the U.K., preserved in Middle Jurassic (about 165 mya) rocks, was likely made by dozens of sauropods moving together… .” Day, J.J., Norman, D.B., Gale, A.S., Upchurch, P., Powell, H.P. 2004. A Middle Jurassic dinosaur trackway site from Oxfordshire, UK. Palaeontology, 47: 319-348.

  p. 47 “These include several sites from the Cretaceous of Korea, one of which has tracks of about twenty large ornithopods heading in the same direction, and another from the Cretaceous of Canada… .” (1) Lockley, M.G., Houck, K., Yang, S.-Y., Matsukawa, M., and Lim, S.-K. 2006. Dinosaur-dominated footprint assemblages from the Cretaceous Jindong Formation, Hallyo Haesang National Park area, Goseong County, South Korea: evidence and implications. Cretaceous Research, 27: 70-101. (2) Currie, P.J. 1983. Hadrosaur trackways from the Lower Cretaceous of Canada. Acta Paleontologica Polonica, 28: 62-74.

  p. 47 “A few ankylosaur tracksites have parallel trackways, suggesting that at least two ankylosaurs were traveling together at the same time.” McCrea et al. (2001).

  p. 47 “Ceratopsian tracks are also uncommon enough to withhold judgment on that aspect of their lives too, although rocks bearing hundreds of bones of the same ceratopsian species tell us these dinosaurs were likely group-oriented also.” (1) Wood, J.M., Thomas, R.G., and Visser, J. 1988. Fluvial processes and vertebrate taphonomy: the upper Cretaceous Judith River Formation, south-central Dinosaur Provincial Park, Alberta, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology, 66: 127-143. (2) Qi, Z., Barrett, P.M., and Eberth, D.A. 2007. Social behaviour and mass mortality in the basal ceratopsian dinosaur Psittacosaurus (Early Cretaceous, People’s Republic of China). Palaeontology, 50: 1023-1029.

  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 Cre
taceous/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).