carnivore evolution & systematics mare 390 dr. turner

Carnivore Evolution & Systematics

MARE 390Dr. Turner

Order Carnivora

5 Families of Marine Mammals

Mustelidae – Sea otterUrsidae – Polar bearPhocidae – Seals (true seal)Otariidae – Sea lions (eared seals)Odobenidae - Walrus }

Pinnipeds

Order CarnivoraAlternative hypotheses for relationships among carnivores

Order CarnivoraMost debate centers around walrus

Order CarnivoraRelationship among carnivores

Morhpological Molecular

Enhydra lutris Lutra lutra

Family Mustelidae

Family Ursidae

Suborder Pinnipedia“feather-footed”

34-36 species – (25% of marine mammals)

19 Phocids

14-16 Otariids1 Odobenid }

Do the EvolutionAdapted to an aquatic existence:

1. Large infraorbital foramen2. Shortened & robust humerus/femur3. Flattened ulna & radius, tibia & fibula4. Elongate digits (I-hand) (I&V-foot)5. Heterodont progressing toward

homodont

Early PinnipedsPinnipedimorph -

Fore & hind flippersmodified forswimming

Spent more time on land than

extant pinnipeds

Early PinnipedsOdobenids – evolved in the North Pacific

during early Miocene – 18 mya

Otariids – evolved in eastern North Pacific during middle Miocene – 11-12 mya

Phocids – evolved in North Pacific during late Miocene – 18 mya

Continents in Early Miocene(20mya)

1- Early pinnipeds 4- Early pinnipeds

Continents in Middle Miocene(12mya)

1- Early phocids, 2 – Monachines & Odobenids, 3-4 - Phocines

Early PinnipedsMonachine seals – evolved in the North

Atlantic (Mediterranean); 1st dispersal to Caribbean, then Hawaii

Phocine seals – evolved in North Atlantic; many in arctic

Ribbon seals evolved in North Pacific, later separated by sister taxa (harp) in the North Atlantic

Bear Pinnipedimorph Otariid Odobenid Phocid

Meet the Pinnipeds

Otariid Odobenid Phocid

Meet the Pinnipeds

Meet the Pinnipeds

Otariid Phocid

Odobenid

Family Otariidae“eared seals” – external ear flaps (pinnae)

California sea lion (O) Hawaiian monk seal (P)

Family OtariidaeTurn hindflippers forward to walk on land

Family OtariidaeOtariids smaller than most phocids

Northern elephant seal (P)Steller’s seal lion (O)

Family OtariidaeShallower divers than phocids

Harbor seal (P)California seal lion (O)

Family OtariidaeDivided into 2 subfamilies:Otariinae (sea lions) & Arctocephalinae (fur seals)

Otariinae (5 genera) Eumetopias, Neophoca, Otaria, Zalophus, Phocarctos

Arctocephalinae (2 genera) Arctocephalus, Callorhinus

Family Otariidae

Extinct Genera

Fur Seals

Sea Lions

Subfamily Otariinae – Sea Lions - Pelage sparse

Subfamily Arctocephalinae – Fur seals - Dense pelage

Family Otariidae

Subfamily OtariinaeEumetopias jubatus- Steller’s sea lion

Neophoca cinerea- Australian sealion

Subfamily OtariinaeOtaris byronis - Southern sea lionOtaria flavescens – South American sea lion

Phocartos hookeri - New Zealand sea lion

Zalophus californianus - California sea lion

Subfamily ArctocephalinaeArctocephalus australis- South American fur seal

Arctocephalus forsteri- New Zealand fur seal

Arctocephalus galapagoensis- Galapagos fur seal

Subfamily ArctocephalinaeArctocephalus gazella- Antarctic fur seal Arctocephalus philippi- Juan Fernandez fur seal

Arctocephalus pusillus- Cape-Australian fur sealtwo subspecies: Cape fur seal - A. pusillus pusillus Australian fur seal - A. pusillus doriferus

Subfamily ArctocephalinaeArctocephalus townsendi- Guadelupe fur seal

Arctocephalus tropicalis- Subantarctic fur seal

Callorhinus ursinus- Northern fur seal

Family Odobenidae

1 species – Odobenus rosmarus - 2 subspecies*

Odobenus r. rosmarus – N. AtlanticOdobenus r. divergens – N. Pacific(Odobenus r. laptevi – Laptev Sea)

Odobenid Classification

Otariid Odobenid

Although tusks (elongate canines) are the most distinguishing trait – evolved from a single line

Odobenid ClassificationArchaic walruses had enlarged canines and narrow premolars – indicative of piscivory rather than specialized mollusk diet today

- more similar to Otariids & Phocids

Odobenid Classification

Divided into 2 subfamilies:Monachinae (monk, elephant, Antarctic)Phocinae (remaining N. Hemisphere seals)

Monachinae (6 genera) Monachus, Mirounga, Lobodon, Ommatophoca, Hydrurga, Leptonychotes

Phocinae (6 genera) Phoca, Histriophoca, Halichoerus, Erignathus, Pagophilus, Cystophora

Family Phocidae

Family Phocidae

Lobodon carcinophagus- crabeater seal

Ommatophoca rossii- Ross seal

Hydrurga leptonyx- leopard seal

Leptonychotes weddellii- Weddell seal

Subfamily Monachinae

Monachus monachus- Mediterranean monk seal

Monachus schauinslandi - Hawaiian monk seal

Monachus tropicalis- Caribbean (West Indian) monk seal

Subfamily Monachinae

Mirounga leonina- southern elephant seal

Mirounga angustirostris- northern elephant seal

Subfamily Monachinae

Phoca vitulina- harbor (common) seal

Phoca largha- largha (spotted) seal

Phoca hispida- ringed seal

Phoca sibirica- Baikal seal

Phoca caspica- Caspian seal

Subfamily Phocinae

Histriophoca fasciata- ribbon seal Halichoerus grypus - grey (gray) seal Erignathus barbatus - bearded seal Pagophilus groenlandicus - harp seal

Cystophora cristata -hooded seal

Subfamily Phocinae

The study of pinniped evolutionary relationships has identified a group of fossil pinnipeds – Desmatophocids

Where’s Walrus

I am the EggmanDesmatophocids have recently been determined to be the common ancestors of phocids

Contradicts previous works which recognized Desmatophocids as otariid pinnipeds

Most morphological data support a phocid & walrus alliance

Molecular data consistently supports uniting otariids & walrus

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