Alligator bite

Crocodyliforms serve as important taphonomic agents, accumulating and modifying vertebrate remains. Previous discussions of Mesozoic crocodyliform feeding in terrestrial and riverine ecosystems have often focused on larger taxa and their interactions with equally large dinosaurian prey. However, recent evidence suggests that the impact of smaller crocodyliforms on their environments should not be discounted. Here we present direct evidence of feeding by a small crocodyliform on juvenile specimens of a 'hypsilophodontid' dinosaur from the Upper Cretaceous (Campanian) Kaiparowits Formation of southern Utah...

BACKGROUND: Crocodilians exhibit a spectrum of rostral shape from long snouted (longirostrine), through to short snouted (brevirostrine) morphologies. The proportional length of the mandibular symphysis correlates consistently with rostral shape, forming as much as 50% of the mandible's length in longirostrine forms, but 10% in brevirostrine crocodilians. Here we analyse the structural consequences of an elongate mandibular symphysis in relation to feeding behaviours. METHODS/PRINCIPAL FINDINGS: Simple beam and high resolution Finite Element (FE) models of seven species of crocodile were analysed under loads simulating biting, shaking and twisting...

Leeches are blood-sucking hermaphroditic parasites that attach to vertebrate hosts, bite through the skin, and suck out blood. When leeches feed, they secrete an anticoagulant (hirudin), which helps them get a full meal of blood. This is the first report of leech removal from external auditory canal. Previous leech involvement cases were explained in nasopharynx, larynx, pharynx, eye, and gastrointestinal tract. Prominent sign of all cases was active bleeding from the leech attachment site; that stopped with leech removal...

Integumentary sensory organs (ISOs) are densely distributed on the jaws of crocodilians and on body scales of members of the families Crocodilidae and Gavialidae. We examined the distribution, anatomy, innervation and response properties of ISOs on the face and body of crocodilians and documented related behaviors for an alligatorid (Alligator mississippiensis) and a crocodylid (Crocodylus niloticus). Each of the ISOs (roughly 4000 in A. mississippiensis and 9000 in C. niloticus) was innervated by networks of afferents supplying multiple different mechanoreceptors...

BACKGROUND: Dakosaurus and Plesiosuchus are characteristic genera of aquatic, large-bodied, macrophagous metriorhynchid crocodylomorphs. Recent studies show that these genera were apex predators in marine ecosystems during the latter part of the Late Jurassic, with robust skulls and strong bite forces optimized for feeding on large prey. METHODOLOGY/PRINCIPAL FINDINGS: Here we present comprehensive osteological descriptions and systematic revisions of the type species of both genera, and in doing so we resurrect the genus Plesiosuchus for the species Dakosaurus manselii...

No abstract text is available yet for this article.

BACKGROUND: Crocodilians have dominated predatory niches at the water-land interface for over 85 million years. Like their ancestors, living species show substantial variation in their jaw proportions, dental form and body size. These differences are often assumed to reflect anatomical specialization related to feeding and niche occupation, but quantified data are scant. How these factors relate to biomechanical performance during feeding and their relevance to crocodilian evolutionary success are not known...

Bacterial cultures and chemical analyses were performed from cloacal and oral swabs taken from 43 American crocodiles Crocodylus acutus and 28 Morelet's crocodiles C. moreletii captured in Quintana Roo State, Mexico. We recovered 47 bacterial species (28 genera and 14 families) from all samples with 51.1% of these belonging to the family Enterobacteriaceae. Fourteen species (29.8%) were detected in both crocodile species and 18 (38.3%) and 15 (31.9%) species were only detected in American and Morelet's crocodiles, respectively...

Bite mechanics and feeding behaviour in Tyrannosaurus rex are controversial. Some contend that a modest bite mechanically limited T. rex to scavenging, while others argue that high bite forces facilitated a predatory mode of life. We use dynamic musculoskeletal models to simulate maximal biting in T. rex. Models predict that adult T. rex generated sustained bite forces of 35 000-57 000 N at a single posterior tooth, by far the highest bite forces estimated for any terrestrial animal. Scaling analyses suggest that adult T...

Animals may be responsible for an array of potentially lethal injuries. Blunt force injuries characteristically involve larger animals such as cattle or horses that may kick, crush, or trample a victim causing head and facial injuries. Farm workers in particular are at high risk of lethal injuries involving the head and torso. Significant blunt trauma may be found in vehicle occupants after collisions with large animals such as camels or moose. Rarely, zookeepers may be crushed by particularly massive animals such as elephants...

The mechanical behavior of mammalian mandibles is well-studied, but a comprehensive biomechanical analysis (incorporating detailed muscle architecture, accurate material properties, and three-dimensional mechanical behavior) of an extant archosaur mandible has never been carried out. This makes it unclear how closely models of extant and extinct archosaur mandibles reflect reality and prevents comparisons of structure-function relationships in mammalian and archosaur mandibles. We tested hypotheses regarding the mechanical behavior of the mandible of Alligator mississippiensis by analyzing reaction forces and bending, shear, and torsional stress regimes in six models of varying complexity...

The microbiology of animal bite wound infections in humans is often polymicrobial, with a broad mixture of aerobic and anaerobic microorganisms. Bacteria recovered from infected bite wounds are most often reflective of the oral flora of the biting animal, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. Our review has focused on bite wound infections in humans from dogs, cats, and a variety of other animals such as monkeys, bears, pigs, ferrets, horses, sheep, Tasmanian devils, snakes, Komodo dragons, monitor lizards, iguanas, alligators/crocodiles, rats, guinea pigs, hamsters, prairie dogs, swans, and sharks...

We describe a fatal attack by a black caiman (Melanosuchus niger) on an 11-year-old child with comments on the reptile's aggression mechanisms and the conditions under which this kind of incident takes place in the Amazon region.

We present a case of vaginal calculus formation following an initial insult of female genital mutilation (FGM) and crocodile bite to the external genital. A literature review made with regards to acute and late complication of female genital mutilation. Female genital cutting existed as early as the 5th century B.C. This ritualistic practice has affected the physical, mental, and social well being of women and undermined the basic reproductive and sexual health rights of the female population. Worldwide, 85-114 million girls and young women are subjected to this dreadful practice...

No abstract text is available yet for this article.

INTRODUCTION: The fishes of continental Brazil have socioeconomic importance due to their potential for sport fishing and commercial and subsistence uses, as seen in the Upper Paraguay River Basin, particularly in the municipalities of the Pantanal region, where it is the second largest economic activity. Injuries caused in professional fishermen are common and poorly studied, as in other regions of the country. METHODS: Data were obtained from questionnaires and interviews with 100 professional fishermen, 50 in each municipality, between December 2008 and October 2009...

Mosquitoes that feed on crocodilians are poorly known, despite the potential role of these exothermic animals as reservoirs of arboviruses. In this article, we assessed the frequency, abundance, and temporal variation of caiman-biting mosquitoes as well as searched for the natural vectors of the blood parasite of caimans, Hepatozoon caimani, in the Pantanal area of central-western Brazil from captures conducted bimonthly from September 2006 to September 2007 and in February 2008. A total of 5,272 mosquitoes belonging to 10 species of five genera was caught on caimans...

OBJECTIVE: Severe injuries and fatalities can occur from an alligator attack. Encounters with alligators appear to be increasing in the United States. This review provides information from alligator attacks reported in the United States as well as infections that may occur after an alligator bite. METHODS: Telephone interviews were conducted with state wildlife offices in all Southern states in order to collect information on the number of alligator bites, nuisance calls, and the estimated alligator population of each state...

Coprolites (fossilized feces) preserve a wide range of biogenic components, from bacteria and spores to a variety of vertebrate tissues. Two coprolites from the Calvert Cliffs outcrop belt (Miocene-aged Chesapeake Group), MD, USA, preserve shark tooth impressions in the form of partial dental arcades. The specimens are the first known coprolites to preserve vertebrate tooth marks. They provide another example of trace fossils providing evidence of prehistoric animal behaviors that cannot be directly approached through the study of body fossils...

BACKGROUND: The fossil record reveals surprising crocodile diversity in the Neogene of Africa, but relationships with their living relatives and the biogeographic origins of the modern African crocodylian fauna are poorly understood. A Plio-Pleistocene crocodile from Olduvai Gorge, Tanzania, represents a new extinct species and shows that high crocodylian diversity in Africa persisted after the Miocene. It had prominent triangular "horns" over the ears and a relatively deep snout, these resemble those of the recently extinct Malagasy crocodile Voay robustus, but the new species lacks features found among osteolaemines and shares derived similarities with living species of Crocodylus...