mammals of the world 5; subclade euungulata: orders perissodactyla & artiodactyla

order perissodactyla characteristics

foot posture unguligrade, foot structure mesaxonic (axis of symmetry passes through middle 3rd digit), alisphenoid canal (AC) present

subclade euungulata

order perissodactyla

family tapiridae - tapirs

snout modified into movable proboscis; nasals heart-shaped; projecting over nasal opening; cheek teeth bilophodont

bilophodont - cusps joined into low ridges called lophs

subclade euungulata

order perissodactyla

family rhinocerotidae - rhinos

only non-artiodactyl with hood ornament (hair horn made of keratin), nasals large and thick (rugose), cheekteeth with simple π-shaped lophodonty (lophodont teeth) 

lophodont

subclade euungulata

order perissodactyla

family equidae - horses, zebras, donkeys

only one distinct digit, nasal bones long and narrow projecting over nasal opening, cheekteeth selenolophodont, postorbital bar present, upper incisors present (compare to Camelidae and Ruminantia)

order artiodactyla/cetartiodactyla

foot posture digitigrade or unguligrade or missing, paraxonic feet if present (axis of symmetry passes between 3rd and 4th digits, even-toed ungulates), alisphenoid canal absent

order artiodactyla

suborder suina

family suidae - hogs & pigs

upper canines larger than lower canines and oriented upwards and outwards, paraoccipital processes elongate

order artiodactyla

suborder suina

family tayassuidae - peccaries

upper canines the same size as lower canines and directed downward, paraoccipital process small

order artiodactyla

suborder whippomorpha

family hippopotamidae- hippos

canines and incisors large, tusklike and directed anteriorly

clade cetacea characteristics

telescoped skull (nares have migrated to the top of the head)

subclade mysticeti characteristics

the baleen whales - no teeth, baleen present, skull profile is convex, no echolocation, lower jaw robust (compare to thin lower jaw in Odontoceti)

clade cetacea

subclade mysticeti

order artiodactyla/cetartiodactyla

family balaenidae - right whales, bowhead whales

 no dorsal fin, baleen long and thin with a sharply arched rostrum, no grooves on throat, feed by swimming with mouth open (skimmers)

clade cetacea

subclade mysticeti

order artiodactyla/cetartiodactyla

family balaenopteridae - blue whales, humpbacks, gray whales

very small dorsal fin, baleen short and broad with a mainly straight rostrum, throat grooves present to feed by inflating their throat and gulping their prey (gulpers) 

subclade odontoceti (toothed whales) characteristics

homodont teeth present, no baleen, skull profile concave, with depression occupied by a fatty organ (“melon”) used in echolocations, thin lowr jaw (“pan bone”); use echolocation

clade cetacea

subclade odontoceti

order artiodactyla/cetartiodactyla

family delphinidae - dolphins

no boss on premaxilla, simple conical cheek teeth, dorsal fin usually present: falcate or pointed

clade cetacea

subclade odontoceti

order artiodactyla/cetartiodactyla

family phocoenidae - porpoises

premaxilla with boss or swelling anterior to nasal opening, teeth usually spade-like, dorsal fin usually present: triangular

clade cetacea

subclade odontoceti

order artiodactyla/cetartiodactyla

family physeteridae - sperm whales

 no boss on premaxilla, strongly symmetrical skull, snout very large, broad, blunt, teeth simple and conical but no upper cheek teeth present, dorsal fin present; sickle-shaped (Kogia) or reduced (Physeter), symphysis of lower jaw long 

suborder tylopoda characteristics

foot posture digitigrade (all other living artiodactyls are unguiligrade), reduction or loss of upper incisors, molars selenodont

order artiodactyla

suborder tylopoda

family camelidae - camels, llamas, alpacas

post orbital bar present, upper canines present (compared to most Ruminantia)

suborder ruminantia characteristics

foot posture unguligrade, loss of uppper incisors, molars selenodont

order artiodactyla

suborder ruminiantia

family antilocapridae - pronghorns

pronghorns (boney core covered by a keratinized sheath that can be forked, shed annually), lacrimal depression absent, nasal and lacrimal bones separated by large opening (nasolacrimal gap), two lacrimal foramina/canals on the side of the orbit

order artiodactyla

suborder ruminiantia

family cervidae - deer, elk

antlers present on pedicels (boney core sheathed in velvet while growing that is usually complexly branched, shed usually annually [velvet & antlers shed separately]), lacrimal depression present, nasolacrimal gap present, two lacrimal foramina/canals at the front edge of or outside the orbi

order artiodactyla

suborder ruminantia

family giraffidae - giraffes

ossicones (composed of dermally derived bones located over the frontal and parietal sutures), no lacrimal depression, nasolacrimal gap present, one lacrimal foramen inside orbit

order artiodactyla

suborder ruminiantia

family bovidae - cattle, goats, sheep

true horn (projecting from frontal bones, permanent and unbranched covered in a hardened keratin sheath), lacrimal depression present or absent, nasolacrimal gap present or absent, single (rarely two) lacrimal foramen/canals present usually on inside orbital rim