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Order Carnivora ≥11 families, >287 species
•Naturally distributed on all continents (except possibly Australia)
•Morphologically & behaviorally diverse
•Economically important in most countries
•Ecologically important
Order Carnivora
Recognition characters (most/all related to carnivory):
Dental features (present in MOST species): •Carnassial shear: P4/M1 (secondarily lost in some taxa) •Canines large, conical •Most have primitive # incisors (3/3)
Cranial features: •Transverse glenoid fossa •Sagittal crest often prominent, well developed •Large brains, well developed zygomatic archOther features:
•Most are medium-sized•Acute senses (hearing, sight, especially smell)•Most are adept cursors---sprinting•Simple stomach (cecum reduced or absent in most sp.)
Glenoid/ mandibular fossa
C-shaped: strong hinge,minimizes lateral movementand facilitates up & downmovement
(e.g., mustelids)
Omnivores (e.g., bears,procyonids) have more “open”glenoid fossa, permitting lateral movement
Postcranial modifications:
•loss or reduction of clavicles(increases stride length)
•fusion of carpal bones (may add support for cursorial locomotion)
Non-cursorial taxa(e.g., ursids, procyonids)
Cursorial taxa(e.g., canids, felids)
Increases stride length
Order Carnivora ≥11 families, >287 species
Suborder Feliformia (“cat like”)Felidae (cats & their relatives)Hyaenidae (hyenas, aardwolves)Herpestidae (mongooses)Viverridae (civets, genets)
Suborder Caniformia (“dog like”)Canidae (dogs & their relatives)Ursidae (bears)Mustelidae (weasels, otters, etc., skunks?)Procyonidae (raccoon, coati, kinkajou)Odobenidae (walrus)Otariidae (sea lions)Phocidae (seals)
Pinnipeds
Felids: “The ultimate killing machines”
Most specialized hunters of the carnivorans, relying almost exclusively on prey that they have killed themselves.
short rostrum=increasedbite force at canines
terminal phalanx, supporting claw
edge of fleshy sheatharound claw
horny claw
elastic ligament holdsclaw in (retracted)pads
tendon of extensor muscle
middle phalanx
Retractile (=retractable) claws? PROTRACTILE!
tendon of flexor muscle
“Hypercarnivory”---too much of agood thing?
Stenotopic: restricted range of habitats or ecological conditions
Eurytopic: wide range of habitatsor ecological conditions
Hypocarnivory
Mesocarnivory
•reduced molars & non-carnassial P’s (=reduced grinding)•enlarged carnassials & canines•short rostrum•meat-only diet
•unreduced or enlarged molars•reduced carnassials•long rostrum•omnivorous diet
Hypercarnivory
SmilodonThylacosmilus(extinct S. Americanhypercarnivorous marsupial)
•Hypercarnivory has evolved several times (and in severalorders)
•Usually correlated with LARGE BODY SIZE...
Cope’s Rule: Evolutionary trend towardslarger body size.
Common among mammals.
Advantages: -Avoid predators-Enhance reproductive success-Improve thermal effiency-Interspecific competition for food-Capture larger prey (prey size often increases over time)
Tradeoff between foraging effort & food acquired imposes energetic constraint.
Smaller carnivores can subist on small prey (e.g., insects, rodents).
Larger carnivores (> ca. 21 g)--small prey not worth the energy expended.
Larger body size leads to HYPERCARNIVORY and overspecialization?
Prey size (cont.)
Hypercarnivory in N. American canids
Canidae---3 subfamilies Caninae Hesperocyoninae† (>28 sp.) Borophaginae† (>68 sp.)
Diverse in Miocene; peak of 25 contemporaneous species. (compare with 7 extant canids in N.S. today)
N. America endemics
1st appearance ofhypercarnivoroushesperocyonines
1st appearance ofhypercarnivorousborophagines
Millions of years ago