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 arch
Other 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 movement
and facilitates up & down
movement
(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)
Fusion of centrale, scaphoid, & lunar bones
of wrist
Carnivora
Most non-carnivorans
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)
Pinnipeds
Phocidae (seals)
Creodonts†
Feliformia
(‘cat-like’)
Caniformia
(‘dog-like’)
Creodonts---Fossil carnivorans, late Cretaceous-Miocene
Outcompeted by more “modern” carnivorans?
18 genera, 40 sp.
All continents ‘cept Austr.,
Antarctica
Felids: “The ultimate killing machines”
Most specialized hunters of the carnivorans,
relying almost exclusively on prey that they
have killed themselves.
short rostrum=increased
bite force at canines
“Big” vs “small” cats
Panthera
Felis
& others
Retractile (=retractable) claws?
PROTRACTILE!
terminal phalanx, supporting claw
edge of fleshy sheath
around claw
horny claw
pads
elastic ligament holds
claw in (retracted)
tendon of extensor muscle
middle phalanx
tendon of flexor muscle
tendon at wrist
holding ligaments in place
ligaments of extensor muscle
terminal phalanx
claw
4 genera, 4 sp.
Africa, SW Asia
18 genera, 37 sp.
Africa, S. & SE Asia
20 genera, 34 sp.
Africa, S. & SE Asia
(Herpestidae)
(Herpestidae)
(Viverridae)
(Viverridae)
(Viverridae)
14 genera, 34 sp.
All continents ‘cept Antarctica
6 genera, 9 sp.
N. & S. America, Eurasia
25 genera, 65 sp.
Worldwide ‘cept
Australia, Madagascar
6 genera, 18 sp.
N. & S. America
“Hypercarnivory”---too much of a
good thing?
Stenotopic: restricted range of habitats
or ecological conditions
Eurytopic:
wide range of habitats
or ecological conditions
Hypercarnivory
•reduced molars &
non-carnassial P’s
(=reduced grinding)
•enlarged carnassials
& canines
•short rostrum
•meat-only diet
Mesocarnivory
Hypocarnivory
•unreduced or
enlarged molars
•reduced carnassials
•long rostrum
•omnivorous diet
Smilodon (extinct
sabre-tooth cat)
Modern felid
masseter muscle relaxes more, allowing
wide open gape
Thylacosmilus
Smilodon
(extinct S. American
hypercarnivorous marsupial)
•Hypercarnivory has evolved several times (and in several
orders)
•Usually correlated with LARGE BODY SIZE...
Cope’s Rule: Evolutionary trend towards
larger 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)
Prey size (cont.)
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?
Hypercarnivory in N. American canids
Canidae---3 subfamilies
Caninae
Hesperocyoninae† (>28 sp.)
Borophaginae†
(>68 sp.)
N. America endemics
Diverse in Miocene; peak of 25 contemporaneous
species. (compare with 7 extant canids in N.S.
today)
Cope’s Rule
Hesperocyoninae†
Borophaginae†
1st appearance of
hypercarnivorous
hesperocyonines
1st appearance of
hypercarnivorous
borophagines
Millions of years ago
“Constraint” Any factor that tends to slow the rate of
adaptive evolution.
Reversal to more generalized morphology rare in
highly specialized taxa.
Hypercarnivory may lead to “adaptive peak” that can’t
be descended...