Download
1 / 120
1.28k likes | 1.97k Views
Carnivora. Carnivora . Carnivory and Carnivora are not synonyms. Most carnivora are specialized for ‘meat’ eating, but certainly not all. Many other non-carnivora consume meat. 2 suborders: Caniformia = dog like: possess alisphenoid canal
E N D
Carnivora • Carnivory and Carnivora are not synonyms. • Most carnivora are specialized for ‘meat’ eating, but certainly not all. • Many other non-carnivora consume meat. • 2 suborders: • Caniformia = dog like: possess alisphenoid canal • Feliformia = cat like: usually lack alisphenoid canal
Carnivora • It is easy to see how cats and canids fit this classification, but how about mustelids? • The 2 suborders are defined on the basis of the auditory bullae and the carotid circulation. • Furthermore, aquatic carnivores (Odobenidae, Otariida, and Phocidae) are pinnipeds (feather footed), while others are fissipeds (split footed). These were once suborders.
Carnivore Morphology • All carnivores have well developed canines. • They possess carnassial teeth formed by upper p4 and lower m1. • Carnassials are designed to shear through muscle and soft tissue, and in some, to slice through bone as well.
Carnivore Morphology • Skull shape reflects feeding strategy. • Compare the structure of the musculature of carnivores and herbivores, as well as the relative position of the mandibular condyle.
Compare the relative positions of the mandibular condyles and importance of primary chewing muscles: Temporalis in carnivores and masseters in herbivores.
Carnivore Morphology • Mandibular fossa differs too. • It has a ‘c’ shape in many, especially mustelids, that permits no lateral movement. • In procyonids and ursids, it is more likely to more ‘open’, allowing more lateral movement. • Why do you think that is?
Note the mandibular fossa in the mustelid and the bear.What function might follow this form?
Carnivore Morphology • An important diagnostic characteristic of carnivores is the structure of the auditory bulla. Recall, this is derived from the angular bone of reptiles. • Recall, reptilian jaw articulation is quadrate-articular, while mammalian is dentary-squamosal.
Carnivore Morphology • Carnivores have 2 forms of auditory bullae • formed by tympanic bone • formed by tympanic and endotympanic. • In feliformes, the bullae are formed by the tympanic and endotympanic, and have a septum in between. • In caniformes, the bullae are formed by the tympanic, and there is no septum.
Carnivore Morphology • Most carnivores have a baculum. • This is sort of interesting. What other mammals have a baculum? Rodents. Why? • Carnivores also have induced ovulation! • Coincidence?
a: red foxb: racoonc: least weaseld: mongoosee: genetf: lion
Carnivore Morphology • Most have anal sace used for intraspecific communication (territoriality - home range etc.) • Sometimes, these are used for defense (skunks). • Absent in ursids, minimal in canids and felids.
Carnivore Morphology • Claws are prominent except in clawless otters (Aonyx), but even here they are vestigal. • Felids and viverids often have retractile claws. • No opposable digits. • Centrale, scaphoid, and lunar are fused.
Carnivore Morphology • Clavicle is reduced or absent. • Permits increased stride length. • Two ways to run faster: 1) increase stride rate or 2) increase stride length. • Note: many ungulates also lack a clavicle. • Some are digitigrade (felids and canids) while others are plantigrade (ursids, procyonids). Difference in speed?
Carnivore Morphology • Size range is considerable: least weasel Mustela nivalis weighs 70g, while Ursus arctos weighs 800kg. What is the implication of this size range? • High protein diet has consequences for the digestive tract (incl. reduced ceacum). • Carnivory, omnivory, and herbivory.
Carnivore Evolution • First fossil carnivore dates to the late Cretaceous: Cimolestes. • Cimolestes is ancestral to both modern carnivores and the creodonts. • Creodonts lasted to the Miocene.
Carnivore Evolution • 2 lineages of early modern carnivores • Viverravidae • Miacidae • Both had P4/M1 carnassials. • Both are from the early Eocene. • Centrale, scaphoid, and lunar were not fused.
Carnivore Evolution • Canids, felids, ursids, viverrids, and mustelids appear by the Oligocene. • Radiation of carnivores mirrors adaptive radiation of vegetation and potential prey items. • Earliest pinnipeds (enaliarctids) date to the late Oligocene.
Felimormia: Felidae • Worldwide dist’n except Australia, New Zealand, Madagascar, Japan, Oceanic Islands, and Poles. • 36 species. • All have shortened rostrum. • What are the consequences of this in terms of olfaction? Bite strength?
Note different proportions of large and small felid skulls. Is this an allometric effect?
Feliformia: Felidae • Felids kill via cervical dislocation, or suffocation. • Note extreme reduction in non-essential dentition.
Feliformia: Felidae • Size ranges from 2kg to 300kg. • Hyoid apparatus is cartilaginous - resulting in ability to roar (purr in fifi). • Claws retractile - except cheetah. • Semi-arboreal. • Papilla on tongue are angled backwards. • Hunting & Social strategies?
Feliformia: Hyaenidae • Old world, large carnivores to 80kg. • 4 genera and 4 species. • Are both effective predators and scavengers. • Feldhammer asserts scavenging may reduce competition between other carnivores and hyaenids. In Serengetti, most cats scavenge from hyaenids.
Feliformia: Hyaenidae • Can regurgitate undigestable items. • Digitigrade w/ nonretractile claws. • Fore-limb dominance is unusual. Why? • Protrusable anal scent glands. • Lack a baculum. • Spotted Females have pseudopenis. Why? Also, females > males. Laughing vocalizations.???
