Common Avian Infection Plagued the Tyrant Dinosaurs

Stanford University, United States of America
PLoS ONE (Impact Factor: 3.23). 09/2009; 4(9):e7288. DOI: 10.1371/journal.pone.0007288
Source: PubMed


Tyrannosaurus rex and other tyrannosaurid fossils often display multiple, smooth-edged full-thickness erosive lesions on the mandible, either unilaterally or bilaterally. The cause of these lesions in the Tyrannosaurus rex specimen FMNH PR2081 (known informally by the name 'Sue') has previously been attributed to actinomycosis, a bacterial bone infection, or bite wounds from other tyrannosaurids.
We conducted an extensive survey of tyrannosaurid specimens and identified ten individuals with full-thickness erosive lesions. These lesions were described, measured and photographed for comparison with one another. We also conducted an extensive survey of related archosaurs for similar lesions. We show here that these lesions are consistent with those caused by an avian parasitic infection called trichomonosis, which causes similar abnormalities on the mandible of modern birds, in particular raptors.
This finding represents the first evidence for the ancient evolutionary origin of an avian transmissible disease in non-avian theropod dinosaurs. It also provides a valuable insight into the palaeobiology of these now extinct animals. Based on the frequency with which these lesions occur, we hypothesize that tyrannosaurids were commonly infected by a Trichomonas gallinae-like protozoan. For tyrannosaurid populations, the only non-avian dinosaur group that show trichomonosis-type lesions, it is likely that the disease became endemic and spread as a result of antagonistic intraspecific behavior, consumption of prey infected by a Trichomonas gallinae-like protozoan and possibly even cannibalism. The severity of trichomonosis-related lesions in specimens such as Tyrannosaurus rex FMNH PR2081 and Tyrannosaurus rex MOR 980, strongly suggests that these animals died as a direct result of this disease, mostly likely through starvation.

  • Source
    • "Uno de los aspectos más interesantes de la paleopatología es que ha permitido inferir pautas de comportamiento en diferentes taxones (Rothschild y Tanke, 1992; Farke et al., 2009; Wolff et al., 2009), así como también diferentes tipos de cortejos sexuales, los cuales han podido ser determinados por las evidencias de lesiones óseas (e.g., Gilmore, 1909, 1912; Droscher, 1976; Blows, 1989). En el presente aporte se reporta el primer registro de displasia coxofemoral avanzada en un ejemplar adulto de Hyperodapedon Huxley 1959 (Diápsida; Archosauromorpha) proveniente de la Biozona Scaphonyx-Exaeretodon-Herrerasaurus (sensu Martínez et al., 2011) de la Formación Ischigualasto (Carniano–Noriano), localidad " Valle Pintado " . "
    [Show abstract] [Hide abstract]
    ABSTRACT: Paleopathology deals with diseases that have left evidence in the fossil record. This field includes the identification of the pathology, and its consequences that on the animal that suffered it. We present the first record of a coxofemoral dysplasia in an Upper Triassic rhynchosaur, being also the first identification of this pathology in the fossil record. 'The specimen is an incomplete skeleton, partially articulated, of Hyperodapedon sanjuanensis (Sill), from the Ischigualasto Formation (Carnian-Norian). Rhynchosaurs were herbivores with a widespread geographical distribution, low species. diversity and a stratigraphic range restricted to Triassic outcrops. The abnormalities described consist of atrophy of the sacrum and pelvis, sclerosed structures in some dorsal vertebrae, and deformation of the left femur. These features are presently characteristic of acetabular dysplasia in dogs. Acetabular dysplasia is a multifactorial disease appearing in the earliest stages of development and increasing throughout life, triggering a secondary joint osteoarthritis in the adult animal and leading to total disability of the affected limb. The advanced stage of the disease affecting the studied specimen reveals a pace known as "fourth grade claudication", stage in which the affected limb stops supporting the body-weight, moving the center of gravity and loading the body-weight onto the other legs. Finally, the adult stage reached by the specimen-despite the severity of their condition-may suggest complex survival strategies in Hyperodapedon sanjuanensis, which need confirmation by future analyses.
    Full-text · Article · Apr 2013 · AMEGHINIANA
  • Source
    • "The presence of Plasmodium dominicana in a Tertiary Dominican Republic amber specimen establishes a minimum age for the genus Plasmodium and places avian malaria in the Americas by the mid-Tertiary, supporting earlier theories that some species responsible for primate malaria could have evolved in the Americas (Poinar 2005b). Indirect evidence based on the frequency of erosive lesions found in tyrannosaurids suggests infection by a Trichomonas gallinae-like protozoan and represents the first report of an avian-transmissible disease in non-avian theropod dinosaurs (Wolff et al. 2009). Cysts similar to those of the extant genus Entamoeba have been preserved in coprolites from the Early Cretaceous , enabling the description of two new genera and species, Entamoebites antiquus (Poinar & Boucot 2006) and Endamoebites proterus (Poinar 2009). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Paleoparasitological research has made important contributions to the understanding of parasite evolution and ecology. Although parasitic protozoa exhibit a worldwide distribution, recovering these organisms from an archaeological context is still exceptional and relies on the availability and distribution of evidence, the ecology of infectious diseases and adequate detection techniques. Here, we present a review of the findings related to protozoa in ancient remains, with an emphasis on their geographical distribution in the past and the methodologies used for their retrieval. The development of more sensitive detection methods has increased the number of identified parasitic species, promising interesting insights from research in the future.
    Full-text · Article · Feb 2013 · Memórias do Instituto Oswaldo Cruz
  • Source
    • "Perforative lesions can be caused mechanically (e.g., impact) or by the death and resorption of bone caused by disease. Wolff et al. (2009) described similar smooth-walled lesions on a number of tyrannosaur mandibles (including TMP 2003.45.84), which they attributed to a trichomonosis-like disease. However, Trichomonas gallinae, which causes avian trichomonosis, does not elicit an osteological response (Stabler 1941; Narcisi et al. 1991), and thus its presence in tyrannosaurs must be considered dubious . "
    [Show abstract] [Hide abstract]
    ABSTRACT: Over the past decade, excavations of a monodominant theropod bonebed from the lower Maastrichtian beds of the Horseshoe Canyon Formation have recovered a minimum number of 26 individuals of the tyrannosaur, Albertosaurus sarcophagus. Examination of skeletal elements from the bonebed revealed a small number of abnormalities from at least two individuals. These include bony spurs (enthesophytes) of unknown origin on three pedal phalanges. Well-healed fracture calluses are present on two rib shafts and a gastralia element. The left dentary of one adult preserves both healed and unhealed parallel bite marks and a perforative lesion attributable to a partially healed, mechanically induced puncture wound. Unfortunately, the limited range in the types and frequencies of pathological changes provides only little information on the distribution of such phenomena but may be suggestive of the overall “health” of the population.Au cours de la dernière décennie, des excavations d'un gisement d'ossements à théropodes monodominant dans des lits du Maastrichtien inférieur de la Formation de Horseshoe Canyon ont produit un minimum de 26exemplaires du tyrannosaure Albertosaurus sarcophagus. L'examen d'éléments squelettiques provenant du gisement a révélé un petit nombre d'anomalies chez au moins deux exemplaires, dont des éperons osseux (enthésophytes) d'origine inconnue sur trois phalanges pédieuses. Des cals de fractures bien consolidées sont présents sur deux diaphyses de côte et un élément de gastralium. L'os dentaire gauche d'un adulte conserve des marques de morsure parallèles guéries et non guéries, ainsi qu'une lésion perforante attribuable à une plaie punctiforme d'origine mécanique partiellement guérie. Malheureusement, la gamme limitée des types et des fréquences de modifications pathologiques ne fournit que peu d'information sur la distribution de ces phénomènes, mais pourrait être un indicateur de la «santé» globale de la population.
    Full-text · Article · Aug 2010 · Canadian Journal of Earth Sciences
Show more