by Brian Switek
an article entitled “The Superiority of Dinosaurs”: Robert T. Bakker, “The Superiority of Dinosaurs,” Discovery 3, no. 2 (1968): 11–22.
mammals were runners-up: Robert T. Bakker, “Dinosaur Physiology and the Origin of Mammals,” Evolution 25, no. 4 (1971): 636–58.
the work of the early archosaur expert: Sterling J. Nesbitt, “The Early Evolution of Archosaurs: Relationships and the Origin of Major Clades,” Bulletin of the American Museum of Natural History 352 (2011), dx.doi.org/10.1206/352.1.
The Coelophysis bonebed: See Edwin H. Colbert, The Little Dinosaurs of Ghost Ranch (New York: Columbia University Press, 1995).
Sterling and his advisor Mark Norell named the animal Effigia okeeffeae: Sterling J. Nesbitt and Mark A. Norell, “Extreme Convergence in the Body Plans of an Early Suchian (Archosauria) and Ornithomimid Dinosaurs (Theropoda),” Proceedings of the Royal Society B 273, no. 1590 (2006): 1045–48, doi:10.1098/rspb.2005.3426.
their close relative Poposaurus: Jacques A. Gauthier et al., “The Bipedal Stem Crocodilian Poposaurus gracilis: Inferring Function in Fossils and Innovation in Archosaur Locomotion,” Bulletin of the Peabody Museum of Natural History 52, no. 1 (2011): 107–26, dx.doi.org/10.3374/014.052.0102.
Some of the earliest known archosaurs: Richard J. Butler et al., “The Sail-Backed Reptile Ctenosauriscus from the Latest Early Triassic of Germany and the Timing and Biogeography of the Early Archosaur Radiation,” PLoS ONE 6, no. 10 (2011), doi:10.1371/journal.pone .0025693.
dinosaur forerunners were walking: Stephen L. Brusatte, Grzegorz Niedz´wiedzki, and Richard J. Butler, “Footprints Pull Origin and Diversification of Dinosaur Stem Lineage Deep into Early Triassic,” Proceedings of the Royal Society B 278, no. 1708 (2010): 1107–13, doi:10.1098/rspb.2010.1746.
Recent discoveries such as Asilisaurus: Sterling J. Nesbitt et al., “Ecologically Distinct Dinosaurian Sister Group Shows Early Diversification of Ornithodira,” Nature 464, no. 7285 (2010): 95–98 doi:10.1038/nature08718.
Eoraptor may have been more of a plant-focused omnivore: Ricardo N. Martinez et al., “A Basal Dinosaur from the Dawn of the Dinosaur Era in Southwestern Pangaea,” Science 331, no. 6014 (2011): 206–10, doi:10.1126/science.1198467.
the razor-jawed Saurosuchus: Oscar Alcober, “Redescription of the Skull of Saurosuchus galilei (Archosauria: Rauisuchidae),” Journal of Vertebrate Paleontology 20, no. 2 (2000): 302–16, dx.doi.org/10.1671/0272-4634(2000)020[0302:ROTSOS]2.0.CO;2.
3. Big Bang Theory
In 2000, the sauropod was reassembled: Bradley Keoun, “Replica of Dinosaur Fossil Gives O’Hare Passengers Monstrous Welcome,” Chicago Tribune, January 20, 2000, articles.chicagotribune.com/2000-01-20/news/0001200303_1_dinosaur-skeleton-brachiosaurus-love-dinosaurs.
That skull—and a few other parts: Michael P. Taylor, “A Re-Evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropod) and Its Generic Separation from Giraffatitan brancai (Janensh 1914),” Journal of Vertebrate Paleontology 29, no. 3 (2009): 787–806, dx.doi.org/10.1671/039.029.0309.
As the British paleontologist Derek Ager: D. U. Ager, Principles of Paleoecology (London: McGraw-Hill, 1963).
Henry Fairfield Osborn pointed to affectionate occasions: Henry Fairfield Osborn, “Tyrannosaurus, Upper Cretaceous Carnivorous Dinosaur (Second Communication),” Bulletin of the American Museum of Natural History 22, no. 16 (1906): 281–96.
George Murray Levick: Robin McKie, “‘Sexual Depravity’ of Penguins that Antarctic Scientist Dared Not Reveal,” Guardian, June 9, 2012, www.guardian.co.uk/world/2012/jun/09/sex-depravity-penguins-scott-antarctic.
The fossil was embedded in the chest: Paul E. Fisher et al., “Cardiovascular Evidence for an Intermediate or Higher Metabolic Rate in an Ornithischian Dinosaur,” Science 288, no. 5465 (2000): 503–505, doi:10.1126/science.288.5465.503.
But in 2011 another team: Timothy P. Cleland, Michael K. Stoskopf, and Mary H. Schweitzer, “Histological, Chemical, and Morphological Reexamination of the ‘Heart’ of a Small Late Cretaceous Thescelosaurus,” Naturwissenschaften 98, no. 3 (2011): 203–11.
a 380-million-year-old armored fish: Per Ahlberg et al., “Pelvic Claspers Confirm Chondrichthyan-Like Internal Fertilization in Arthrodires,” Nature 460 (2009): 888–89, doi:10.1038/nature08176.
Scipionyx that was found in Italy: Cristiano Dal Sasso and Marco Signore, “Exceptional Soft Tissue Preservation in a Theropod Dinosaur from Italy,” Nature 392 (1998): 383–87, doi:10.1038/32884.
Inside the hips: Tamaki Sato et al., “A Pair of Shelled Eggs Inside a Female Dinosaur,” Science 308, no. 5720 (2005): 375, doi:10.1126/science.1110578.
According to the ornithologist Kevin McCracken: Kevin G. McCracken, “The 20-cm Spiny Penis of the Argentine Lake Duck (Oxyura vittata),” The Auk 117, no. 3 (2000), 820–25.
Other ducks, male and female, are similarly famous: Patricia L. R. Brennan et al., “Coevolution of Male and Female Genital Morphology in Waterfowl,” PLoS ONE 2, no. 5 (2007), e418, doi:10.1371/journal.pone.0000418.
As determined by: P.L.R. Brennan et al., “Independent Evolutionary Reductions of the Phallus in Basal Birds,” Journal of Avian Biology 39, no. 5 (2008): 487–92, doi:10.1111/j.2008.0908-8857.04610.x.
male alligators, crocodiles, and gharials have penises, too: Brandon C. Moore, Ketan Mathavan, and Louis J. Guillette Jr., “Morphology and Histochemistry of Juvenile Male American Alligator (Alligator mississippiensis) Phallus,” The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology 295 (2012): 328–37, doi:10.1002/ar.21521; Thomas Ziegler and Sven Olbort, “Genital Structures and Sex Identification in Crocodiles,” Crocodile Specialist Group Newsletter 26, no. 3 (2007): 16–17.
In 2006, Steve Wang: Steve C. Wang and Peter Dodson, “Estimating the Diversity of Dinosaurs,” Proceedings of the National Academy of Sciences 103, no. 37 (2006): 13601–605, doi:10.1073/pnas.0606028103.
Peter Dodson highlighted the trouble: P. Dodson, “Taxonomic Implications of Relative Growth in Lambeosaurine Hadrosaurs,” Systematic Zoology 24, no. 1 (1975): 37–54.
the Canadian paleontologists David Evans and Robert Reisz: D. C. Evans and R. R. Reisz, “Anatomy and Relationships of Lambeosaurus magnicristatus, a Crested Hadrosaurid Dinosaur (Ornithischia) from the Dinosaur Park Formation, Alberta,” Journal of Vertebrate Paleontology 27, no. 2 (2007): 373–93.
During the 1990s, some paleontologists: Kenneth Carpenter, “Variation in Tyrannosaurus rex,” in Dinosaur Systematics: Approaches and Perspectives, ed. Kenneth Carpenter and Philip J. Currie (New York: Cambridge University Press, 1990), 141. P. L. Larson, “Tyrannosaurus sex,” in Dino Fest: Proceedings of a Conference for the General Public, ed. Gary D. Rosenberg and D. L. Wolberg, Paleontological Society Special Publications 7 (Knoxville: The Paleontological Society, 1994), 139.
As paleontologists later found: Gregory M. Erickson, A. Kristopher Lappin, and Peter Larson, “Androgynous rex—The Utility of Chevrons for Determining the Sex of Crocodilians and Non-Avian Dinosaurs,” Zoology 108, no. 4 (2005): 277–86, dx.doi.org/10.1016/j.zool.2005.08.001.
no one has yet found an unequivocal case: Kevin Padian and Jack R. Horner, “The Evolution of ‘Bizarre Structures’ in Dinosaurs: Biomechanics, Sexual Selection, Social Selection or Species Recognition?,” Journal of Zoology 283, no. 1 (2011): 3–17, doi:10.1111/j.1469-7998.2010.00719.x.
In 2000, a special specimen of T. rex: Jack Horner and James Gorman, How to Build a Dinosaur: Extinction Doesn’t Have to Be Forever (New York: Dutton, 2009), 61–67.
The Tyrannosaurus had been pregnant: Mary H. Schweitzer, Jennifer L. Wittmeyer, and John R. Horner, “Gender-Specific Reproductive Tissue in Ratites and Tyrannosaurus rex,” Science 308, no. 5727 (2005): 1456–60, doi:10.1126/science.1112158.
Andrew Lee and Sarah Werning: A. H. Lee and S. Werning, “Sexual Maturity in Growing Dinosaurs Does Not Fit Reptilian Growth Models,” PNAS 105, no. 2 (2008): 582–87, doi:10.1073/pnas.0708903105.
In his children’s book The Year
of the Dinosaur: Edwin H. Colbert, The Year of the Dinosaur, illustrated by Margaret Colbert (New York: Charles Scribner’s Sons, 1977), 101.
William Service added a little more color: William Stout and William Service, The Dinosaurs: A Fantastic View of a Lost Era (New York: Byron Preiss Books, 1981), 13–14.
the strange adornments: Scott D. Sampson, “Bizarre Structures and Dinosaur Evolution,” in Dinofest International: Proceedings of a Symposium Held at Arizona State University, ed. Donald L. Wolberg, Edmund Stump, and Gary D. Rosenberg (Philadelphia: The Academy of Natural Sciences, 1997), 39–45.
But in 1996 the zoologists: Robert E. Simmons and Lue Scheepers, “Winning by a Neck: Sexual Selection in the Evolution of Giraffe,” The American Naturalist 148, no. 5 (1996): 771–86.
Phil Senter applied the same idea to sauropods: Phil Senter, “Necks for Sex: Sexual Selection as an Explanation for Sauropod Dinosaur Neck Elongation,” Journal of Zoology 271, no. 1 (2007): 45–53, doi:10.1111/j.1469-7998.2006.00197.x.
But the sauropod experts: Michael P. Taylor, Mathew J. Wedel, and Darren Naish, “Head and Neck Posture in Sauropod Dinosaurs Inferred from Extant Animals,” Acta Palaeontologica Polonica 5, no. 2 (2009): 213–20, doi:10.4202/app.2009.0007; M. P. Taylor et al., “The Long Necks of Sauropods Did Not Evolve Primarily Through Sexual Selection,” Journal of Zoology 285, no. 2 (2011): 150–61, doi:10.1111/j.1469- 7998.2011.00824.x.
Giraffes, too, have been shown to gain a feeding advantage: Elissa Z. Cameron and Johan T. du Toit, “Winning by a Neck: Tall Giraffes Avoid Competing with Shorter Browsers,” The American Naturalist 169, no. 1 (2007): 130–35; G. Mitchell, S. J. van Sittert, and J. D. Skinner, “Sexual Selection Is Not the Origin of Long Necks in Giraffes,” Journal of Zoology 278, no. 4 (2009): 281–86, doi:10.1111/j.1469-7998.2009.00573.x; R. E. Simmons and R. Altwegg, “Necks-for-Sex or Competing Browsers? A Critique of Ideas on the Evolution of Giraffe,” Journal of Zoology 282, no. 1 (2010): 6–12, doi:10.1111/j.1469-7998.2010.00711.x.
The biomechanics expert R. McNeill Alexander: R. M. Alexander, Dynamics of Dinosaurs and Other Extinct Giants (New York: Columbia University Press, 1989), 57–58.
However they did it: Timothy E. Isles, “The Socio-Sexual Behaviour of Extant Archosaurs: Implications for Understanding Dinosaur Behaviour,” Historical Biology 21, nos. 3–4 (2009): 139–214.
Among other things, Mallison discovered: Heinrich Mallison, “CAD Assessment of the Posture and Range of Motion of Kentrosaurus aethiopicus Hennig, 1915,” Swiss Journal of Geosciences 103, no. 2 (2010): 211–33, doi:10.1007/s00015-010-0024-2; H. Mallison, “Defense Capabilities of Kentrosaurus aethiopicus Hennig, 1915,” Palaeontologia Electronica 14, no. 2 (2011), 10A:25p.
4. The Dinosaurs, They Are a-Changin’
The AMNH paleontologist Mark Norell: Mark A. Norell et al., “A Theropod Dinosaur Embryo and the Affinities of the Flaming Cliffs Dinosaur Eggs,” Science 266, no. 5186 (1994): 779–82, doi:10.1126/science.266.5186.779.
Robert Reisz and colleagues found that: R. R. Reisz et al., “Embryonic Skeletal Anatomy of the Sauropodomorph Dinosaur Massospondylus from the Lower Jurassic of South Africa,” Journal of Vertebrate Paleontology 30, no. 6 (2010): 1653–65, doi:10.1080/02724634.2010.521604
And there were more eggs: R. R. Reisz et al., “Oldest Known Dinosaurian Nesting Site and Reproductive Biology of the Early Jurassic Sauropodomorph Massospondylus,” PNAS 109, no. 7 (2012): 2428–33, doi:10.1073/pnas.1109385109.
One of the most fantastic dinosaur nesting grounds: Lucas E. Fiorelli et al., “The Geology and Palaeoecology of the Newly Discovered Cretaceous Neosauropod Hydrothermal Nesting Site in Sanagasta (Los Llanos Formation), La Rioja, Northwest Argentina,” Cretaceous Research 36 (2011): 94–117, dx.doi.org/10.1016/j.cretres.2011.12.002.
paleontologists have found burrows: David J. Varricchio, Anthony J. Martin, and Yoshihiro Katsura, “First Trace and Body Fossil Evidence of a Burrowing, Denning Dinosaur,” Proceedings of the Royal Society B 274, no. 1616 (2007): 1361–68, doi:10.1098/rspb.2006.0443.
According to David Varricchio: D. J. Varricchio, “A Distinct Dinosaur Life History?,” Historical Biology 23, no. 1 (2011): 91–107, doi:10.1080/08912963.2010.500379.000.
It all started in July of that year: John B. Scannella and John R. Horner, “Torosaurus Marsh, 1891, is Triceratops Marsh, 1889 (Ceratopsidae: Chasmosaurinae): Synonymy Through Ontogeny,” Journal of Vertebrate Paleontology 30, no. 4 (2010): 1157–68, dx.doi.org/10.1080/02724634.2010.483632.
discovered its remains in 1887: Kenneth Carpenter, “‘Bison’ alticornis and O.C. Marsh’s Early Views on Ceratopsians,” in Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs, ed. K. Carpenter (Bloomington: Indiana University Press, 2007), 349.
Mark Goodwin, the University of California, Berkeley, paleontologist: John R. Horner and Mark B. Goodwin, “Major Cranial Changes During Triceratops Ontogeny,” Proceedings of the Royal Society B 273, no. 1602 (2006): 2757–61, doi:10.1098/rspb.2006.3643.
During the 1980s and 1990s: Catherine A. Forster, “Species Resolution in Triceratops: Cladistic and Morphometric Approaches,” Journal of Vertebrate Paleontology 16, no. 2 (1996): 259–70; John H. Ostrom and Peter Wellnhofer, “The Munich Specimen of Triceratops with a Revision of the Genus,” Zitteliana 14 (1986): 111–58.
It wasn’t until 2006: Mark B. Goodwin et al., “The Smallest Known Triceratops Skull: New Observations on Ceratopsid Cranial Anatomy and Ontogeny,” Journal of Vertebrate Paleontology 26, no. 1 (2006): 103–12.
Indeed, a different dinosaur: John B. Scannella and John R. Horner, “‘Nedoceratops’: An Example of a Transitional Morphology,” PLoS ONE 6, no. 12 (2011): e28705, doi:10.1371/journal.pone.
“My third horn”: Limericks, Wait Wait … Don’t Tell Me!, NPR, August 7, 2010. www.npr.org/templates/story/story.php?storyId=129039425.
What’s more, Farke has noted: Andrew A. Farke, “Anatomy and Taxonomic Status of the Chasmosaurine Ceratopsid Nedoceratops hatcheri from the Upper Cretaceous Lance Formation of Wyoming, U.S.A,” PLoS ONE 6, no. 1 (2011): e16196, doi:10.1371/journal.pone.0016196; Nicholas R. Longrich and Daniel J. Field, “Torosaurus Is Not Triceratops: Ontogeny in Chasmosaurine Ceratopsids as a Case Study in Dinosaur Taxonomy,” PLoS ONE 7, no. 2 (2012): e32623, doi:10.1371/journal.pone.0032623.
when Peter Dodson surveyed: P. Dodson, “Taxonomic Implications of Relative Growth in Lambeosaurine Hadrosaurs,” Systematic Zoology 24, no. 1 (1975): 37–54, www.jstor.org/stable/2412696.
The same was true of “Brachyceratops”: Charles W. Gilmore, “Brachyceratops, a Ceratopsian Dinosaur from the Two Medicine Formation of Montana, with Notes on Associated Fossil Reptiles,” United States Geological Survey Professional Paper 103 (1917); Andrew T. McDonald, “A Subadult Specimen of Rubeosaurus ovatus (Dinosauria: Ceratopsidae), with Observations on Other Ceratopsids from the Two Medicine Formation,” PLoS ONE 6, no. 8 (2011): e22710, doi:10.1371/journal.pone.0022710.
But according to Nicolás Campione: Nicolás E. Campione and David C. Evans, “Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America,” PLoS ONE 6, no. 9 (2011), e25186, doi:10.1371/journal.pone.0025186.
In 1946, Charles Gilmore: C. W. Gilmore, “A New Carnivorous Dinosaur from the Lance Formation of Montana,” Smithsonian Miscellaneous Collections 106 (1946): 1–19.
paleontologists regularly mistook young tyrannosaurs: Takanobu Tsuihiji et al., “Cranial Osteology of a Juvenile Specimen of Tarbosaurus bataar (Theropoda, Tyrannosauridae) from the Nemegt Formation (Upper Cretaceous) of Bugin Tsav, Mongolia,” Journal of Vertebrate Paleontology 31, no. 3 (2011): 497–517.
As Thomas Carr: Thomas D. Carr, “Craniofacial Ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria),” Journal of Vertebrate Paleontology 19, no. 3 (1999): 497–520, www.jstor.org/stable/4524012; T. D. Carr and Thomas E. Williamson, “Diversity of Late Maastrichtian Tyrannosauridae (Dinosauria: Theropoda) from Western North America,” Zo
ological Journal of the Linnean Society 142, no. 4 (2004): 479–523; Lawrence M. Witmer and Ryan C. Ridgely, “The Cleveland Tyrannosaur Skull (Nanotyrannus or Tyrannosaurus): New Findings Based on CT Scanning, with Special Reference to the Braincase,” Kirtlandia 57 (2010): 61–81; Denver W. Fowler et al., “Reanalysis of ‘Raptorex kriegsteini’: A Juvenile Tyrannosaurid Dinosaur from Mongolia,” PLoS One 6, no. 6 (2011): e21376, doi:10.1371/journal.pone.0021376.
5. Jurassic Thunder
Brachiosaurus was as big as dinosaurs got: Elmer S. Riggs, “Brachiosaurus altithorax, the Largest Known Dinosaur,” American Journal of Science (Series 4) 15, no. 88 (1903): 299–306, doi:10.2475/ajs.s4-15.88.299; Ruth E. Moore, Evolution, Young Readers Nature Library (Alexandria, VA: Time-Life Books, 1979), 94–95.
As Matt Wedel remarked: Mathew J. Wedel, “A Monument of Inefficiency: The Presumed Course of the Recurrent Laryngeal Nerve in Sauropod Dinosaurs,” Acta Palaeontologica Polonica 57, no. 2 (2012): 251–56, dx.doi.org/10.4202/app.2011.0019.
As the paleontologist Stephen Jay Gould: Stephen J. Gould, “The Panda’s Thumb,” in The Panda’s Thumb: More Reflections in Natural History (New York: W. W. Norton, 1980), 19.
The paleontologist Edwin Colbert and his collaborators: Edwin H. Colbert, Raymond B. Cowles, and Charles M. Bogert, “Temperature Tolerances in the American Alligator and Their Bearing on the Habits, Evolution, and Extinction of the Dinosaurs,” Bulletin of the American Museum of Natural History 86 (1946): 327–74.
a landmark study of mammal bones: Meike Köhler et al., “Seasonal Bone Growth and Physiology in Endotherms Shed Light on Dinosaur Physiology,” Nature 487 (2012): 358–61, doi:10.1038/nature11264.
As the paleontologist Kevin Padian remarked: Kevin Padian, “Evolutionary Physiology: A Bone for All Seasons,” Nature 487 (2012): 310–11, doi: 10.1038/nature11382.