Skip to main content Accessibility help

Trace fossils of possible parasites inside the gut contents of a hadrosaurid dinosaur, Upper Cretaceous Judith River Formation, Montana

  • Justin Tweet (a1), Karen Chin (a2) and A. A. Ekdale (a3)

Tiny sinuous trace fossils have been found within probable gut contents of an exceptionally preserved specimen of a hadrosaurid dinosaur, Brachylophosaurus canadensis, from the Judith River Formation of Montana. Approximately 280 examples of the trace fossils were observed in 19 samples of gut region material. The tubular structures typically are about 0.3 mm across. Many have thin calcareous linings or layers, and some exhibit fine surficial striae. At least two dozen of these trace fossils share walls with adjacent tubular traces, and this association can extend for several millimeters. While the trace fossils share some characteristics with fine rhizoliths, these features are most consistent with tiny burrows, or possibly body impressions, of worms (vermiform organisms) of uncertain biologic affinity. Such trace fossils have not been reported previously, and herein described as Parvitubulites striatus n. gen. n. sp. Either autochthonous (parasites) or allochthonous (scavengers) worms may have created the trace fossils, but taphonomic factors suggest that autochthonous burrowers are more likely. Several lines of evidence, such as constant diameters and matching directional changes, suggest that the paired trace fossils were made by two individuals moving at the same time, which implies sustained intraspecific contact. Parvitubulites striatus provides a rare record of interactions between terrestrial, meiofaunal-sized, soft-bodied invertebrates and a dinosaur carcass. The evidence that the worms may have parasitized a living hadrosaur and subsequently left traces of intraspecific behavior between individual worms adds unique information to our understanding of Mesozoic trophic interactions.

Hide All
Bader, K., 2005, The use of forensic entomology in dinosaur taphonomy at a quarry in the Upper Jurassic Morrison Formation in northeastern Wyoming: Journal of Vertebrate Paleontology, v. 25 (Supplement to Number 3), p. 33A.
Boyd, D.W., 1975, False or misleading traces, in Frey, R.W., ed., The Study of Trace Fossils: A Synthesis of Principles, Problems, and Procedures in Ichnology: New York, Springer-Verlag, p. 6583.
Braithwaite, C.J.R., Taylor, J.D., and Glover, E.A., 2000, Marine carbonate cements, biofilms, biomineralization, and skeletogenesis: some bivalves do it all: Journal of Sedimentary Research, v. 70, p. 11291138.
Britt, B., Dangerfield, A., and Greenhalgh, B., 2005, Burrowed dinosaur bones: evidence of Cretaceous osteophagous beetles: Journal of Vertebrate Paleontology, v. 25 (Supplement to Number 3), p. 39A.
Bromley, R.G., 1996, Trace Fossils (second edition): London, Chapman & Hall, 361 p.
Chamberlain, C.K., 1975, Recent lebensspuren in nonmarine aquatic environments, in Frey, R.W., ed., The Study of Trace Fossils: a Synthesis of Principles, Problems, and Procedures in Ichnology: New York, Springer-Verlag, p. 431458.
Chin, K., and Bishop, J., 2007, Exploited twice: bored bone in a theropod coprolite from the Jurassic Morrison Formation of Utah, USA, in Bromley, R.G., Buatois, L.A., Mángano, M.G., Genise, J.F., and Melchor, R.N., eds., Sediment-Organism Interactions: A Multifaceted Ichnology: SEPM Special Publication No. 88, Tulsa, Society for Sedimentary Geology, p. 377–385.
Chin, K., and Gill, B.D., 1996, Dinosaurs, dung beetles, and conifers: participants in a Cretaceous food web: Palaios, v. 11, p. 280285.
Chin, K., Hartman, J.H., and Roth, B., 2009, Opportunistic exploitation of dinosaur dung: fossil snails in coprolites from the Upper Cretaceous Two Medicine Formation of Montana: Lethaia, v. 42, p. 185198.
Croll, N.A., 1971, The Behaviour of Nematodes: Their Activities, Senses, and Responses, New York, St. Martin’s Press, 117 p.
Dash, M.C., 1983, Biology of Enchytraeidae (Oligochaeta): Dehradun, International Book Distributers, 171 p.
Durand, N., Monger, H.C., and Canti, M.G., 2010, Calcium carbonate features, in Stoops, G., Marcelino, V., and Mees, F., eds., Interpretation of Micromorphological Features of Soils and Regoliths: Amsterdam, Elsevier, p. 150195.
Edwards, C. A., and Bohlen, P.J., 1996, Biology and Ecology of Earthworms, (third edition): London, Chapman & Hall, 426 p.
Ekdale, A.A., and de Gibert, J.M., 2010, Paleoethologic significance of bioglyphs: fingerprints of the subterraneans: Palaios, v. 25, p. 540545.
Gao, T.-P., Shih, C.-K., Xu, X., Wang, S., and Ren, D., 2012, Mid-Mesozoic flea-like ectoparasites of feathered or haired vertebrates: Current Biology, v. 22, p. 732735.
Genise, J.F., Bellosi, E.S., Verde, M., and González, M.G., 2011, Large ferruginized palaeorhizospheres from a Paleogene lateritic profile of Uruguay: Sedimentary Geology, v. 240, p. 8596.
Goodey, J.B., 1963, Soil and Freshwater Nematodes (second edition): New York, John Wiley & Sons, Inc., 544 p.
Hasiotis, S.T., Fiorillo, A.R., and Hanna, R.R., 1999, Preliminary report on borings in Jurassic dinosaur bones: evidence for invertebrate-vertebrate interactions, in Gillette, D.D., ed., Vertebrate Paleontology in Utah: Salt Lake City, Utah Geological Survey Miscellaneous Publication 99-1, Utah Geological Survey, p. 193–200.
Higgins, R.P., and Thiel, H., eds., 1988, Introduction to the Study of Meiofauna: Washington, D.C., Smithsonian Institution Press, 488 p.
Huang, D., Engel, M.S., Cai, C., Wu, H., and Nel, A., 2012, Diverse transitional giant fleas from the Mesozoic era of China: Nature, v. 483, p. 201204.
Huettel, R.N., 2004, Reproductive behavior, in Gaugler, R., and Bilgrami, A.L., eds., Nematode Behaviour: Cambridge, CABI Publishing, p. 127149.
Jaillard, B., Guyon, A., and Maurin, A.F., 1991, Structure and composition of calcified roots, and their identification in calcareous soils: Geoderma, v. 50, p. 197210.
Klappa, C.F., 1980, Rhizoliths in terrestrial carbonates: classification, recognition, genesis and significance: Sedimentology, v. 27, p. 613629.
Khormali, F., Abtahi, A., and Stoops, G., 2006, Micromorphology of calcitic features in highly calcareous soils of Fars Province, southern Iran: Geoderma, v. 132, p. 3146.
Kirkland, J.I., Delgado, D.R., Chimedtseren, A., Hasiotis, S.T., and Fox, E.J., 1998, Insect? bored dinosaur skeletons and associated pupae from the Djadokhta Fm. (Cretaceous, Campanian): Journal of Vertebrate Paleontology, v. 18 (Supplement to Number 3), p. 56A.
Kraus, M.J., and Hasiotis, S.T., 2006, Significance of different modes of rhizolith preservation to interpreting paleoenvironmental and paleohydrologic settings: examples from Paleogene paleosols, Bighorn Basin, Wyoming, U.S.A.: Journal of Sedimentary Research, v. 76, p. 633646.
Moussa, M.T., 1970, Nematode fossil trails from the Green River Formation (Eocene) in the Uinta Basin, Utah: Journal of Paleontology, v. 44, p. 304307.
Murphy, N.L., Trexler, D., and Thompson, M., 2007, “Leonardo,” a mummified Brachylophosaurus from the Judith River Formation, in Carpenter, K., ed., Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs: Bloomington and Indianapolis, Indiana University Press, p. 117133.
Nolte, M.J., Greenhalgh, B.W., Dangerfield, A., Scheetz, R.D., and Britt, B.B., 2004, Invertebrate burrows on dinosaur bones from the Lower Cretaceous Cedar Mountain Formation near Moab, Utah, U.S.A.: Geological Society of America Abstracts with Programs, v. 36, no. 5, p. 379.
O’Connor, F.B., 1967, The Enchytraeidae, in Burges, A., and Raw, F., eds., Soil Biology: London and New York, Academic Press, p. 213257.
Paik, I.S., 2000, Bone chip-filled burrows associated with bored dinosaur bone in floodplain paleosols of the Cretaceous Hasandong Formation, Korea: Palaeogeography, Palaeoclimatology, and Palaeoecology, v. 157, p. 213225.
Payne, J.A., 1965, A summer carrion study of the baby pig Sus scrofa Linnaeus: Ecology, v. 46, p. 592602.
Poinar, G. Jr., and Boucot, A.J., 2006, Evidence of intestinal parasites of dinosaurs: Parasitology, v. 20, p. 245249.
Poinar, G. Jr., and Poinar, R., 2008, What Bugged the Dinosaurs? Insects, Disease, and Death in the Cretaceous, Princeton, Princeton University Press, 264 p.
Retallack, G.J., 1983, Late Eocene and Oligocene Paleosols from Badlands National Park, South Dakota: Geological Society of America Special Paper 193, Boulder, Geological Society of America, 82 p.
Roberts, E.M., Rogers, R.R., and Foreman, B.Z., 2007, Continental insect borings in dinosaur bone: examples from the Late Cretaceous of Madagascar and Utah: Journal of Paleontology, v. 81, p. 201208.
Robinson, A.F., 2004, Nematode behavior and migrations through soil and tissue, in Chen, Z.X., Chen, S.Y., and Dickson, D.W., eds., Nematology: Advances and Perspectives Vol. 1: Cambridge, Tsinghua University Press and CABI Publishing, p. 330405.
Rogers, R.R., 1992, Non-marine borings in dinosaur bones from the Upper Cretaceous Two Medicine Formation, northwestern Montana: Journal of Vertebrate Paleontology, v. 12, p. 528531.
Sarjeant, W.A.S., 1975, Plant trace fossils, in Frey, R.W., ed., The Study of Trace Fossils: a Synthesis of Principles, Problems, and Procedures in Ichnology: New York, Springer-Verlag, p. 163179.
Schieber, J., 2002, The role of an organic slime matrix in the formation of pyritized burrow trails and pyrite concretions: Palaios, v. 17, p. 104109.
Seilacher, A., 1967, Fossil behavior: Scientific American, v. 217, p. 7280.
Smith, K.G.V., 1986, A Manual of Forensic Entomology: Ithaca, Cornell University Press, 205 p.
Tweet, J.S., Chin, K., Murphy, N.L., and Braman, D.R., 2008, Probable gut contents within a specimen of Brachylophosaurus canadensis (Dinosauria: Hadrosauridae) from the Upper Cretaceous Judith River Formation of Montana: Palaios, v. 28, p. 624635.
Verrecchia, E.P., and Verrecchia, K.E., 1994, Needle-fiber calcite: a critical review and a proposed classification: Journal of Sedimentary Research, v. A64, p. 650664.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Paleontology
  • ISSN: 0022-3360
  • EISSN: 1937-2337
  • URL: /core/journals/journal-of-paleontology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed