Paenungulata: elephants, sea cows, & hyraxes.
Phylogeny: Afrotheria : Chrysochloroidea + Macroscelidea + (Tubulidentata + * : Hyracoidea + (Sirenia + Proboscidea)).
Links: Phylo.gen; Paenungulata; SIRENIA: Manatees, Dugong, and Sea Cow APW 020617.
Fr lwEc of Afr & Eur; fl lwOc.
Small rodent or rabbit-like forms with some large extinct relatives. Short skull with short rostrum; dental formula 1/2, 0,0, 4/4, 3/3; upper incisors, widely separated, triangular, tusk-like & ever-growing, with enamel only on lingual face; lower incisors wedge-shaped & tricuspid; small diastema present; upper molars with ectoloph & 2 cross-lophs; lowers lilambdodont (?); deep lower jaw; orbital bar present; zygomatic arch complete; jugal large & contributes to glenoid; small auditory bullae; compact body; tail highly reduced; clavicle absent; digits 4(5?)/3, with flat nails ("hoof-like"?) except for claw on pes 2; mesaxonic (III); palm/sole covers metapodials with thick, elastic, glandular skin which can be cupped for traction; stomach simple, with 3 ceca; mainly herbivorous, with some omnivory; metabolism low & behavioral thermoregulation common; able climbing & jumping; fairly wide variety of guilds and ecological settings.
Links: Introduction to the Hyracoidea; Animal Diversity Web: Order Hyracoidea: Family Procaviidae; hyrax page (but the line drawing has 2/3 incisors, no postorbital bar & jugal does not contribute to glenoid. Hyracoid?); Hyracoidea; Other Videos; Order HYRACOIDEA; Order Hyracoidea: Hyraxes; Schliefer; Hyracoidea; Subungulates.
Image: Procavia capensis from Utah's Hogle Zoo (the object which looks like a cigarette hanging out of the Hyrax's mouth is one of its modified upper incisors).
Sirenia: Manatees (Trichechus)& dugongs (Dugong).
Large coastal marine herbivores. Skull short, with strongly developed premaxillary; dentition variable among species; primitively 5(!) premolars; essentially modern postcranium from earliest known remains of mEc age; nostrils valvular, extending posteriorly beyond anterior rim of orbit; nasals reduced or absent; dentary deep; rostrum and dentary deflected ventrally at anterior end; tympanic semi-circular; periotic not connected to skull (as in cetaceans); heavy pachostotic ribs; muscular tail with flukes; digits 5/0, with forelimb as flipper; strongly developed deltopectoral crest [T+01]; hindlimbs absent; pelvis vestigial; lungs unlobed, long, & oriented horizontally with a horizontal diaphragm (used for floatation); heavy, dense bone; large, mid-gut cecum; very slow metabolism and low-nutrient diet; metabolism & relatively poor insulation restrict range to warmer waters; complex oral signals; social behavior not well known.
Links: Encyclopedia Smithsonian: References on the Sirenia; Introduction to the Sirenia; Animal Diversity Web: Order Sirenia; Dugong Page (English); Sirenia; Manatee Skull - Trichechus manatus; Dugongs: The UAE is one of the last refuges of these endangered sea-mammals APW 020617.
References: Thewissen et al. 2001) [T+01].
Image: from Welcome to Dubai - the desert's most exciting city!.
checked ATW050727, revised MAK120319