| SYSTEMATIC BIOLOGY |
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| CLASS MAMMALIA |
Mammalia (mam-A-li-a) is derived from a single Latin root that means breast (mamma). The name refers to the occurrence of milk glands, a synapomorphic character of this group.
The mammals are synapsids and a sister group to the "mammal-like reptiles", the Eosynapsida. In general, the mammals have a suite of synapomorphic characters that define them as a monophyletic group. They have hair, and a single lower tooth-bearing jaw bone (the dentary) that articulates with the squamosal. The teeth are replaced one time and show a differentiation between incisors, canines, and cheek teeth (premolars and molars). The mammary glands are sweat glands that have been modified to deliver milk, a protein and lipid-rich substance, to newborn mammals before they can ingest food on their own. Though not unique to mammals, they are endothermic and capable of high levels of activity. Mammals have diversified to occupy almost all terrestrial and aquatic environments.
The approximately 4,700 extant mammals can be divided into three very unequal groups: the monotremes, the marsupials, and the placentals. The monotremes are highly modified burrowing animals that are restricted to the continent of Australia and represented by only three extant species: the platypus, echidna, and spiny anteater. All are toothless; furthermore, the platypus has an unusual horny beak (see Figure A). They retain the primitive character of laying eggs rather than gestating the young within their bodies.
Marsupials are characterized by having a marsupium, a protective pouch in which the almost fetus-like young resides and feeds attached to the nipple from the time it is born until it can move about on its own. Their teeth have a dental formula similar to other mammals, but they replace only the premolars and molars. The southern continental distribution of marsupials is a consequence of their having evolved on Gondwanaland during the Cretaceous period. The South American marsupials are called the Ameridelphids and are represented primarily by opossums (see Figure B), mainly omnivorous animals that have prehensile tails. The exchange of animals between North and South America after the completion of the Central American land bridge, led to the mass extinction of many diverse South American marsupials during the past 5 million years. Only the Virginia possum (Didelphis virginiana) of all the marsupials has made its way into North America where it has become very successful.
Australia also broke away from Gondwanaland, but it never became connected to a major land mass. Thus, its marsupial fauna remained diverse and rich until the introduction of placental mammals by humans (who also are placental mammals). Perhaps, the most renowned members of the australidelphid marsupials are the kangaroos and wallabies (Figure C). Large kangaroos are the ecological equivalents of gregarious herbivores like the ungulates of North America (e.g. Bison) and Africa (e.g. antelope). Aside from terrestrial mammals, the Australian marsupials include arboreal and fossorial species. They also range from carnivores to omnivores as well as herbivores. They also include species that specialize on eating nectar, insects, and eucalyptus leaves.
Placental, also called the eutherian, mammals comprise more than 90% of all extant mammals. They are characterized by the occurrence of a placenta, a connection between the uterine wall and the developing young. Placental mammals, because they allow the gestation of a fairly well-developed offspring before birth, also have a relatively large birth canal. Though they appeared much earlier in the Cretaceous period in which much of their diversification occurred, the successful exploitation of almost all continents and oceans by the placental mammals has occurred over the last 65 million years. Much of the organization of eutherians seems to be associated with plate tectonics and is reflected in the names of the four distinct clades: the Afrotheria, Xenarthra, Laurasiatheria, and Euarchontoglires.
Six orders form a monophyletic group of very different animals that evolved in Africa and, therefore, are called the Afrotheria. The largest members of the group are the elephants (see Figure D) and dugongs. Most are small to medium animals: elephant shrews, aardvarks, tenrecs, and hyrax. Although molecular evidence suggests a strong, ancient relationship between these taxa, structural synapomorphies characteristic of the Afrotheria have not been identified.
Xenarthra is a monophyletic group that has been recognized for some time (formerly the order Edentata). The extant taxa include armadillos and sloths (see Figure E), which, as the old ordinal name implies, no teeth. However, this is not characteristic of the group. The extinct giant sloth had more than 100 teeth, a very large number for a mammal. Structural synapomorphies include extra joints between some of the trunk and tail vertebrae. Also, the ischium and the ilium are fused to the first caudal vertebra.
Animals of the Laurasiatheria evolved on the northern supercontinent of Laurasia after the breakup of Pangea. The diversity in form, habitat, and size in this group is astounding and contains the largest and among the smallest of all mammals. The Laurasiatheria includes 7 or 8 orders depending on how the cetaceans and artiodactyls are lumped together into a group called the Cetartiodactyla. This group (here treated as a superorder) is an unlikely collection of animals like pigs, cows, camels together with whales and dolphins. As remarkable as the collection seems, the relationship has been confirmed by fossil, molecular, and anatomical evidence (Thewissen and Williams 2002). Furthermore, the emerging story of whale evolution has become one of the most exciting demonstrations of macroevolution to have emerged in vertebrate paleohistory.
Other orders of the Laurasiatheria include Chiroptera (bats), Perissodactyla (horses, rhinoceroses, and tapirs), Carnivora (cats, dogs, mongooses, bears, weasels, seals, walruses, etc.), Eulipotyphla (contains moles and shrews, animals formerly included in a group called the Insectivora), and the Pholidota (scaly anteaters). Though these animals appeared in Laurasia, they entered and became important members of the landscape in all continents and all oceans. Perhaps, most notable are the Chiroptera, one of the few groups of vertebrates to achieve true flight.
The Euarchonotoglires, sometimes called the Supraprimates, are sisters to the Laurasiatheria and include the rodents, hares, primates, tree shrews and flying lemurs. The rodents and hares are very speciose and comprise more than 40% of all living mammals. The primates include lemurs, monkeys (see Figure H), and apes. Our species, Homo sapiens, is a primate and one of the most successful species on earth occurring in almost all biomes and transforming the globe. The Euarchonotoglires and Laurasiatheria together are in a clade called the Boreotheria (animals of the northern continents) and contain the crown taxa of the mammals.
| HIERARCHICAL TAXONOMY OF THE CLASS MAMMALIA. The following descriptions come from Benton (2005), Kemp (2005), and the Animal Diversity Web (from the University of Michigan Museum of Zoology). The structure of the following system is also based, in part, on the phylogenetic treatment by Mikko's Phylogeny Web (from the Finnish Museum of Natural History) and Kielan-Jaworowska et al. (2004). Taxa in red are extinct. | |
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FIGURE A. Duck-billed Platypus, a monotreme from Australia. |
FIGURE B. A Virginia possum, a member of the Ameridelphia branch of marsupials. |
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FIGURE C. A kangaroo, a large bipedal member of the Australidelphia branch of marsupials. |
FIGURE D. An African elephant, an Afrotheria placental mammal. |
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FIGURE E. A sloth, a Xenarthra placental mammal. |
FIGURE F. A horse (Equus), a Laurasiathera placental mammal. |
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FIGURE G. A blue whale, a member of the Laurasiatheria, is the largest animal that has ever lived. |
FIGURE H. A spider monkey in the rainforest of Costa Rica. It is a member of the Euchontoglires. |
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Image
of Platypus from: http://www.epa.qld.gov.au/images/nature_conservation/platypus.jpg Image of Virginia Possum (Didelphis) from: http://condor.depaul.edu/~gandrus/jpg/pics/possum.jpg Image of the African Elephant from: http://www.bioinquiry.vt.edu/SouthAfrica/species.html Image of the horse came from the Systematic Biology collection. Image of the sloth from: http://arnica.csustan.edu/boty1050/Evolution/sloth_extant.jpg Image of the Blue Whale from: http://www.yoto98.noaa.gov/books/whales/whale3.htm |
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CLASS MAMMALIA In general, the mammals have a suite of synapomorphic characters that define them as a monophyletic group. They have hair, and a single lower tooth-bearing jaw bone (the dentary) that articulates with the squamosal. The teeth are replaced one time and show a differentiation between incisors, canines, and cheek teeth (premolars and molars). They are endothermic and capable of high levels of activity. Mammals have diversified to occupy almost all terrestrial and aquatic environments. One group, the bats, has achieved true flight. Living mammals can be divided into the following major groups: MARSUPIALIA
PLACENTALIA
SUBCLASS
UNNAMED+ ORDER
UNNAMED FAMILY
UNNAMED Known
from fragments of the braincase. Elements
present indicate a mammalian organization of the skull, including the enclosure
of the expanded brain by sheets of bone. Upper
Triassic Adelobasileus FAMILY
SINOCONODONTIDAE It
had the same skull features as Adelobasilius. In
addition, it had a fully-developed dentary-squamosal jaw joint.
The middle ear was approaching the mammalian state.
The cheek teeth did not occlude well and seem to have been replaced
through the individual’s life. Such
indeterminate growth of the teeth and skull was a primitive feature similar to
that of the cynodonts. Lower
Jurassic Sinoconodon SUBCLASS MAMMALIAFORMES INFRACLASS
UNNAMED+ ORDER
UNNAMED It
retained the extradentary bones in the lower jaw which served in hearing.
The cheek teeth were differentiated between premolars and molars.
It seemed to have developed the mammalian diphydont or single tooth
replacement. All cheek teeth
occlude. The lower jaw was narrower
than the upper jaw, a condition common to most mammals.
Ribs only in the thoracic region. The
forelimbs were still somewhat sprawling. The
hind legs, however, were erect. They
seem to have had determinate growth (animals were of one size).
Also, they seem to have been nocturnal (inferred from the architecture of
the brain case which emphasized parts of the brain responsible for hearing and
smell) and enthothermic (inferred from the small size and adaptations to rapid
respiration). Also, likely they were
insectivorous. Thus, they were like
shrews. FAMILY
MORGANUCODONTIDAE Morganucodon,
Megazostrodon INFRACLASS HOLOTHERIA SUPERORDER UNNAMED ORDER
UNNAMED+ Known
only from teeth and jaw fragments, it had clear mammalian features of the cheek
teeth, primarily 3 cusps- a large central cusp and two smaller lateral cusps. Lower
Jurassic FAMILY
KUEHNEOTHERIIDAE Kuehneotherium ORDER
DOCODONTA+ Also
known from fragmentary skeletal evidence, mainly jaws and teeth.
These had the tricusp molars as well as differentiated incisors and
canines. Middle
and upper Jurassic Docodon ORDER
UNNAMED+ These
animals had cheek teeth that interlock in a mortar and pestle grinding action
called a tribosphenic-like molar (others have an anterior and lingual shelf of
bone rather than a full cupule in the lower molar). Middle
Jurassic to lower Cretaceous FAMILY
AUSKTRIBOSPHENIDAE Ausktribosphenos,
Bishops, Asfaltomylos, Ambondro This order includes two extant animals, the platypus and echidna. Both animals reproduce by laying eggs, and have an interclavicle bone, both primitive characters. However, both extant monotreme groups are toothless as adults and difficult to compare to the early mammalian fossils. Fortunately, the platypus has teeth that do not erupt and are absorbed before the formation of the horny beak. Those teeth and the earlier ones show similarities with the ausktribosphenid teeth. Lower Cretaceous to the present:
Steropodon+ FAMILY ORNITHORHYNCHIDAE Duck-Billed
Platypus. These are aquatic mammals
of streams and lakes of Platypus FAMILY TACHYGLOSSIDAE Echidnas and
Spiny Anteaters. These are
medium-sized mammals of Echidna,
Zaglossus.. ORDER
TRICONODONTA+ Mainly
known from isolated tricuspid molars, but some skeletal remains have been found,
the most spectacular of which was Jeholodens,
a burrowing anomal. It was and
insectivore with plantigrade stance (feet flat on the ground).
Both fore and hind limbs were sprawling.
Middle
Jurassic to Upper Cretaceous Triconodont, Jeholodens ORDER
MULTITUBERCULATA+ The
largest group of Mesozoic mammals. The
multituberculates were omnivorous and rodent-like.
As in rodents, the incisors are long and separated from the cheek teeth
by a gap. There were no canine
teeth. Unlike rodents, the last
premolar forms a large shearing surface. They
had two small epipubic bones (also seen in the extant monotremes and other
extinct Cretaceous groups). At least one appeared to have been arboreal with a
prehensile tail and hind feet that can swivel backwards like a squirrel.
Upper
Jurassic to upper Eocene. Kamptobaatar,
Nemegtbaatar, Ptilodus ORDER SYMMETRODONTA+ The
middle cusp of the tricusp molars was offset toward the tongue.
Some had a very large coronoid process and extended angular process at
the back angle of the jaw. Lower
Cretaceous Spalacotherium, Zhangeotherium, Cusafontia ORDER
DELTATHEROIDA+ These
animals stood at the inflexion point of the holotherians and the therians.
They had cheek teeth (form and replacement pattern; see below) that
shared characters with the marsupials. Also,
the pattern of cranial vascularization was marsupial in form.
Upper
Cretaceous Deltatheridium INFRACLASS THERIA (a clade of marsupial + placental mammals) SUPERORDER MARSUPIALIA Marsupials replace only the premolars and molars. The anterior teeth are not replaced. Marsupials have 3 premolars and 4 molars. ORDER DIDELPHIMORPHIA Opossums.
Marsupials of Central and Upper Cretaceous to the present FAMILY DIDELPHIDAE Alphadon+ Subfamily
Caluromyinae (Wooly Opossums): Caluromys,
Calurmysiops, Glironia. Subfamily
Didelphinae (American Opossums): Chironectes,
Didelphis, Gracilinanus, Lestodelphys, Lutreolina, Marmosa, Marmosops,
Metachirus, Micoureus, Monodelphis, Philander, Thylamys. ORDER PAUCITUBERCULATA Shrew Possums. FAMILY CAENOLESTIDAE Shrew
Possums. These animals seem to be
insectivores of western Upper Oligocene to present Caenolestes,
Lestoros, Rhyncholestes, Paleothentes+ FAMILY
ARGYROLAGIDAE+ Argyrolagus
was similar in form to a kangaroo rat; adapted to hopping and large cheek teeth.
Argyrolagus FAMILY
CAROLOAMEGHINIDAE+ Small
insectivores. Early
Cenozoic Roberthoffestetteria ORDER
SPARASSODONTA+ Carnivores FAMILY
BORHYAENIDAE They
were somewhat dog-like with short limbs. Paleocene
to Pliocene Prothylacynus FAMILY
THYLACOSMILIDAE These
animals developed long saber-like upper canines that fit into a sheath formed by
the lower jaw. The canine had
indeterminate growth. Upper
Miocene to Pliocene Thylacosmilus ORDER MICROBIOTHERIA Oligocene to present FAMILY MICROBIOTHERIDAE Monitos del
Monte. They live in humid vegetation
of the mountainous regions of souther Dromiciops,
Microbiotherium+, Khasia+ ORDER DASYUROMORPHIA Marsupial mice and rats, cat-like animals, and the Tasmanian wolf FAMILY DASYURIDAE Dasyurids.
Arboreal and terrestrial; Antechinus,
Dasycercus, Dasykaluta, Dasyurus, Murexia, Myoictis, Neophascogale, Ningaui,
Parantechnicus, Phascogale, Phascolosorex, Planigale, Pseudantechnicus,
Sarcophilus, Sminthopsis. FAMILY MYRMECOBIIDAE Numbats.
Ant-eating marsupials of southern Myrmecobius. FAMILY
THYLACINIDAE + Tasmanian
Wolf. Once common from New Guinea
to
Tasmania, now likely extinct.
The marsupial has many dog-like features, including its posture and head. Thylacinus. ORDER PERAMELEMORPHIA Bandicoots and bilbis. Early Miocene to present FAMILY PERAMELIDAE Bandicoots
and Bilbies. Ground-dwelling animals of drier habitas of Chaeropus,
Isodon, Macrotis, Perameles. FAMILY PERORYCTIDAE Spiny
Bandicoots and Mouse Bandicoots. Humid
tropical forests of Echymipera,
Microperoryctes, Peroryctes, Rhynchomeles. ORDER NOTORYCTEMORPHIA Marsupial moles FAMILY NOTORYCTIDAE Marsupial
Moles. Fossorial animals of the
deserts of Notoryctes. ORDER DIPROTODONTIA Very diverse order including:
Australian possums, gliding phalangers (including the marsupial lion),
wallabies, kangaroos, koalas, wombats. Lower Miocene to present FAMILY ACROBATIDAE Feathertail
Gliders. Small arboreal animals of Acrobates,
Distoechurus. FAMILY BURRAMYIDAE Pygmy
Possums. Small arboreal animals of Burramys,
Cercartetus. FAMILY PETAURIDAE Gliders,
Leadbeater’s Possum, and Striped Possum. Arboreal
animals of Dactylopsila,
Gymnobelidius, Petaurus. FAMILY POTOROIDAE Bettongs, Potoroos, and Rat Kangaroos. They are terrestrial mammals of open areas of Australia. They have large hind legs and feet and hop like rabbits, but can come up to a bipedal hop at high speeds. They have a tail that is somewhat prehensile. They are omnivores and seem to have specialized on underground fungi, tubers, and insects. Like the macropodids, their premolars are replaced by a single premolar with a shearing edge. Aepyprymnus,
Bettongia, Caloprymnus, Hypsiprymnodon, Potorous. FAMILY MACROPODIDAE Kangaroos
and Wallabies. Animals are terrestrial or arboreal and tend to be herbivores
(grazers and browsers) which occur over most of Dendrolagus,
Dorcopsis, Dorcopsulus, Lagochestes, Lagotrophus, Macropus, Onychogalea,
Petrogale, Setonix, Thylogale, Wallabia. FAMILY PSEUDOCHEIRIDAE Ringtailed
Possums. Small to medium-sized
arboreal animals of Hemibelideus,
Petaluroides, Petropseudes, Pseudocheirus, Pseudochirops. FAMILY TARSIPEDIDAE Honey
Possum. They are small arboreal
animals of southwestern Tarsipes. FAMILY PHALANGERIDAE Brushtail
Possums, Cuscuses, and Phalangers. They
are semi-arboreal animals of Ailurops,
Phalanger, Spilocuscus, Strigocuscus, Trichosurus, Wyulda. FAMILY VOMBATIDAE (PHASCOLOMYIDAE) Wombats.
Stocky terrestrial animals of Lasiorhinus,
Vombatus. FAMILY PHASCOLARCTIDAE Koalas.
Small (~60cm high) teddy-bear arboreal animals of Phascolarctos.
SUPERORDER PLACENTALIA (EUTHERIA) ORDER TUBULIDENTATA Aardvarks. These are terrestrial
animals of Miocene to present FAMILY ORYOCTEROPIDAE Orycteropus. ORDER AFROSORISCIDA FAMILY TENRECIDAE Tenrecs.
These are insectivores of Miocene to present. Subfamily Geogalinae (Large-Eared Tenrecs): Geogale. Subfamily
Oryzorictinae (Aquatic Tenrecs, Rice Tenrecs, and Shrew Tenrecs): Limnogale,
Microgale, Oryzoryctes. Subfamily
Tenrecinae (Tenrecs): Echinops, Hemicentetes,
Setifer, Tenrecs. Centetes,
, Ericulus, , ,. FAMILY POTAMOGALIDAE Otter
Shrews. Aquatic animals of western and central Micropotamogale,
Potamogale. FAMILY CHRYSOCHLORIDAE Golden
moles. These are fossorial
insectivores of south and east-central Miocene to present Ambltsomus,
Calcochloris, Chlorotalpa, Chrysochloris, Chrysopalax, Erimitalpa. ORDER MACROSCELIDEA Elephant Shrews. The elephant shrews have dentition that resemble rodents (long incisors) and a body that resembles shrews. Middle Eocene to present FAMILY MACROSCELIDIDAE Jumping or Elephant Shrews.
These terrestrial leaping mammals are from south and east-central Elephantulus,
Macroscelides, Petrodromus, Rhynchodon. PAENUNGULATA ORDER HYRACOIDEA Hyraxes, Dassies, and Conies.
They are herbivores from sub-Saharan Eocene to present FAMILY PROCAVIIDAE Hyraxes. Dendrohyrax,
Heterohyrax, Procavia. ORDER SIRENIA Sea cows. Early forms had short legs. Later the forelegs became paddle-like and the hindlegs became reduced to a few bones that do not emerge from the animal and acquired a whale-like tail. Animals of tropical and subtropical coastal waters where they eat water plants. Their dentition is reduced to a few molars. Also, they have a short elephant-like proboscis. Eocene to present Pezosiren+, Dusisiren+ FAMILY DUGONGIDAE Dugongs and
Sea Cows. They are fully marine
animals of eastern Dugong,
Hydrodamalis+ FAMILY TRICHECHIDAE Manatees.
These are marine animals of the coastal regions of southeastern US, the Trichechus. ORDER PROBOSCIDEA The developed a reduced jugal and orbit that opens to the maxilla. Enlarged second incisors; lower canines and first premolars absent. Modifications in the limbs to support great weight. Presumably, all had extensions of the nose that became the trunk in large forms that could not lower their heads to the ground. SUBORDER
UNNAMED+ FAMILY
MOERITHERIIDAE These
were the earliest forms. They had a
deep skull with second incisors of both upper and lower jaws enlarged and
projecting forward. They were
relatively small semi aquatic animals, much like small hippos. Lower
Eocene to Oligocene Phosphatherium,
Moeritherium FAMILY
DEINOTHERIIDAE These
animals had a pair of recurved lower tusks and no upper tusks.
Eocene
to middle Pleistocene Deinotherium SUBORDER ELEPHANTIFORMES These animals lost more of their premolars FAMILY
MAMMUTIDAE+ The
paleomastodontids. A pair of
elongate upper tusks; molars with rounded cusps. Upper
Eocene to Miocene FAMILY
GOMPHOTHERIIDAE+ Upper
and lower incisors elongate as tusks. Mastodon-type
teeth with mounded cusps. Miocene Gomphotherium FAMILY
STEGODONTIDAE+ Molars
with more incised (higher) cusps. Pliocene Stegodon FAMILY ELEPHANTIDAE Elephants
and Mammoths. Large terrestrial
animals of Elephas,
Loxodonta, Mammuthus+. These animals have a suite of unique characters including extra joints between some of the trunk and tail vertebrae. Also, the ischium and the ilium are fused to the first caudal vertebra. They have reduced teeth or no teeth at all. ORDER CINGULATA FAMILY DASYPODIDAE Armadillos.
They are terrestrial animals that range from the central Upper Paleocene to present Subfamily Chlamyphorinae (Fairy Armidillos and Pichiciegos): Chlamyphorus. Subfamily
Dasypodinae (Armadillos): Cabassous,
Chaetophractus, Dasypus, Euphractus, Priodontes, Tolypeutes, Zaedyus. FAMILY
GLYPTODONTIDAE+ The
glyptodonts were similar to armadillos, but many grew to very large size and
were much more heavily armored. They
had continuously growing cheek teeth. Some
had a spiked club at the end of the tail. Pliocene
to Pleistocene Glyptodon ORDER PILOSA Sloths and South American Anteaters Miocene to present FAMILY MYRMECOPHAGIDAE South
American Anteaters. These are
remarkable animals of Central and Lower Miocene to the present. Cyclopes,
Myrmecophaga, Tamandua. FAMILY BRADYPODIDAE Three-Toed
Sloths. They are arboreal animals
that range from Bradypus,
Hapalops+ FAMILY MEGALONYCHIDAE Two-Toed
Sloths. These are arboreal animals
that range from Miocene to
the present. Choloepus. FAMILY
MEGATHERIIDAE+ Giant
Ground Sloths. Megatherium FAMILY MYLODONTIDAE? BOREOEUTHERIA ORDER
LEPTICTIDA+ Small
shrew-like animals; long snouts and small sharp teeth (insectivores).
They retain the jugal. Paleocene
to Oligocene Leptictis ORDER
ANAGALIDA+ Herbivorous.
These animals had broad grinding molars.
Rabbit-like in appearance. They
retain a postorbital process. Paleocene Anagale ORDER
APATEMYIDA+ Insectivorous.
Their dentition seemed to be a mixture of rodent and shrew. The incisors
were long and project forward. Paleocene
to Oligocene Sinclairella ORDER
TAENIODONTA Herbivores.
The forelimbs and forefeet were larger than the hind limbs and hind feet.
Claws were narrow and recurved (for digging?).
Paleocene
to Eocene Stylinodon ORDER
TILLIODONTIA Herbivores.
Some were bear-sized. Their
teeth indicate that they fed on tough plants. Paleocene
to Eocene ORDER
PANTODONTA Herbivores,
relatively large (pig to hippo-sized) that resembled ground sloths.
They had massive limbs and plantigrade feet; some may have been
semi-erect. Paleocene
to Oligocene Titanoides ORDER
PANTOLESTA These
resembled otters with flattened skulls. Their
enlarged molars suggest that they may have fed on shellfish.
Stomach contents also indicate that they fed on fish. Paleocene
to Oligocene Buxolestes ORDER
DINOCERATA Also
known as the uintotheres, these animals were very large and built much like a
rhinoceros. They had bony
protuberances on the skull and large canines that may have been used for ritual
combat. Paleocene
and lower Eocene Uintatherium ORDER LIPOTYPHLA This order includes most of the animals once regarded as Insectivora. SUBORDER ERINACEOMORPHA The hedgehogs. Early forms were dog-sized and covered with stiff hairs. Later forms evolved the spines characteristic of today’s hedgehog. Eocene to present FAMILY
ADAPISORICIDAE+ Cretaceous. FAMILY ERINACEIDAE Hedgehogs
and Rat Shrews. These are terrestrial mammals of Subfamily
Erinaceinae (Hedgehogs): Atelerix, Erinaceus,
Hemiechinus, Mesechinus. Subfamily
Hylomyinae (Gymnures and Moonrats):
Echinosorex, Hylomys, Podogymnura. Deinogalerix+. SUBORDER SORICOMORPHA The shrews and moles. W-shaped pattern of ridges on the upper molars is diagnostic for the group. Middle Paleocene to present FAMILY SORICIDAE Shrews.
World-wide (except Subfamily
Crocidura (White-Toothed Shrews): Congosorex, Crocidura, Diplomesodon, Feroculus, Myosorex, Paracrocidura,
Ruwenzorisorex, Scutisorex, Solisorex, Suncus, Surdisorex, Sylvisorex. Subfamily
Soricinae (Red-Toothed Shrews): Anourosorex, Blarina, Blarinella, Chimarrogale, Cryptotis, Megasorex, Microsorex,
Nectogale, Neomys, Notiosorex, Praesorex. Sorex, Soriculus. Domnina+. FAMILY TALPIDAE Moles and
Desmans. Fossorial and aquatic animals of Eocene to the present. Subfamily Desmaninae (Desmans): Desmana, Galemys. Subfamily Talpinae (Moles): Condylura, Euroscaptor, Mogera, Nesoscaptor, Neurotrichus, Parascalops, Parascaptor, Scalopus, Scapanulus, Scapanus, Scaptochirus, Scaptonyx, Talpa, Urotrichus. Subfamily Uropsillinae (Chinese Shrew Moles): Uropsilus. ORDER CHIROPTERA The bats use fingers 2-5 as the frame for their wings. The shoulder girdle is adapted to large flight muscles on the scapula, ribs, and sternum. Hind feet can turn backwards. Upper Paleocene to present SUBORDER MEGACHIROPTERA Fruit bats. This suborder has a single family. FAMILY
PTEROPODIDAE Flying Foxes
and Oligocene to
the present. Subfamily
Macroglossinae (Blossom Bats, Dawn Bats, Long-Tongued Bats): Eonycteris,
Macroglossus, Megaloglossus, Melonycteris, Notopteris, Syconycteris. Subfamily
Pteropodinae (Old World Friut Bats): Acerodon,
Aethalops, Alionycteris, Balionycteris, Boneia, Casinycteris, Chironax,
Cynopterus, Dobsonia, Dyacopterus, Eidolon, Epomophorus, Epomops, Haplonycertis,
Hypsignathus, Latidens, Megaerops, Micropteropus, Myonycteris, Nanonycteris,
Neopteryx, Nyctimene, Otopteropus, Paranyctimene, Penthetor, Plerotes,
Ptenochirus, Pteralopex, Pteropus, Rousettus, Scotonycteris, Sphaerias,
Styloctenium, Thoopterus. SUBORDER
MICROCHIROPTERA Insect-eating bats.
Mainly small with relatively large and elaborate ears, many with
nose-leaves, both of which function in echolocation.
Index finger without a claw; tail usually long.
Found from the tropics through temperate latitudes.
Teeth broad with many cusps. Most
are sociable; some hibernate. FAMILY
CRASEONYCTERIDAE Bumblebee
Bat and Hog-Nosed Bat. Tiny bats of
the Craseonycteris. FAMILY
EMBALLONURIDAE Sac-Winged Bats and Tomb Bats. Insectivores of tropical and subtropical areas world-wide. Most notable is the glandular sac on the leading edge of the wing. The tail is in a membranous sheath. They use echlolocation to catch prey and for communication. Upper Eocene
to the present. Balantiopteryx,
Centronycteris, Coelura, Cormura, Cyttarops, Diclidurus, Emballonura, Mosia,
Peropteryx, Rhynchonycteris, Saccolaimus, Saccopteryx, Taphozous. FAMILY
FURIPTERIDAE Smoky Bats
and Thumbless Bats. Insectiverous
bats of Amorphochilus,
Furipterus. FAMILY
MEGADERMATIDAE False
Vampire Bats. Cardioderma,
Lavia, Macroderma, Megaderma. FAMILY
MOLOSSIDAE Free-Tailed
Bats. They occur from Chaerephon,
Cheiromeles, Eumops, Molossops, Molossus, Mops, Mormopterus, Myopterus,
Nyctinomops, Otomops, Promops, Tadarida. FAMILY
MORMOOPIDAE Ghost-Faced
Bats, Moustached bats, and Naked-Backed Bats.
They occur from Pleistocene
to the present. Mormoops,
Pteronotus. FAMILY
MYSTACINIDAE Mystacina. FAMILY
MYZOPODIDAE Old-World
Sucker-Footed Bats. These bats are
restricted to Pleistocene
to the present. Myzopoda. FAMILY
NATALIDAE Funnel-Eared
Bats. They are small insect eating
bats of lowland areas from northern Natalus. FAMILY
NOCTILIONIDAE Bulldog Bat
or Fish-Eating Bat. Noctilio. FAMILY
NYCTERIDAE Slit-Faced
Bats. Bats of tropical forests and
arid regions from Nycteris. FAMILY
PHYLLOSTOMIDAE Miocene to
the present. Subfamily
Brachyphyllinae (Antillian Fruit-Eating Bats): Brachyphylla. Subfamily
Carolliinae Little Bats and Short-Tailed Bats): Carollia, Rhynophylla. Subfamily
Desmodontinae (True Vampire Bats. Tropical South and Subfamily
Glossophaginae (Long-Nosed Bats, Long-Tongued Bats, Tailless Bats): Anoura,
Choeroniscus, Glossophaga, Hylonycteris, Leptonycteris, Lychnonycteris,
Monophyllus, Musonycteris, Scleronycteris. Subfamily
Lonchophyllinae (Nectar Bats): Lionycteris,
Lonchophylla, Platalina. Subfamily
Phyllonycterinae (Flower Bats): Erophylla,
Phyllonycteris. Subfamily
Phyllostomatinae (Round-Eared Bats, Spear-Nosed Bats, Sword-Nosed Bats): Chrotopteris,
Lonchorhina, Macrophyllum, Macrotus, Micronycteris, Mimon, Phylloderma,
Phyllostomus, Tonatia, Trachops, Vampyrum. Subfamily
Stenodermatinae (Fruit-Eating Bats, Tent-Making bats, Yellow-Shouldered Bats): Ametrida,
Ardops, Ariteus, Artibeus, Centurio, Chiroderma, Ectophylla, Mesophylla,
Phyllops, Platyrrhinus, Pygoderma, Sphaeronycteris, Stenoderma, Sturnira,
Uroderma, Vampyressa, Vampyrodes. FAMILY
RHINOLOPHIDAE Horseshoe
Bats and Old-World Leaf-Nosed Bats. Bats of temperate and tropical areas of Subfamily
Hipposiderinae (Leaf-Nosed bats): Anthops,
Asellia, Anselliscus, Cloeotis, Coelops, Hipposideros, Paracoelops,
Rhinonicteris, Triaenops. Subfamily
Rhinolophinae (Horshoe Bats): Rhinolophus. FAMILY
RHINOPOMATIDAE Mouse-Tailed
Bats. Bats of deserts and semi-deserts northeastern Rhinopoma. FAMILY
THRYOPTERIDAE Disc-Winged
Bats. Bats of the neotropics.
They have suction structures on their wrists and ankles (like the
myzopodids of Thryoptera. FAMILY
VESPERTILIONIDAE Common Bats.
Almost global; Subfamily Kerivoulinae (Wooly Bats): Kerivoula. Subfamily Miniopterinae (Bent-Winged Bats and Long-Fingered Bats): Miniopterus. Subfamily Murininae (Hairy-Winged Bats and Tube-Nosed Bats): Harpiocephalus, Murina. Subfamily
Tomopeatinae (Blunt-Eared Bats): Tomopeas. Subfamily
Vespertillioninae (Evening Bats, Long-Eared Bats, Myotis Bats, Pipistrelles,
Serotines): Antrozous,
Barbastella,
Chalinolobus,
Eptesicus,
Euderma,
Eudiscopus,
Glischropus,
Hesperoptenus,
Histiotus,
Ia,
Idionycteris,
Laephotis,
Lasionycteris,
Lasiurus,
Mimetillus,
Myotis,
Nyctalus,
Nycticeius,
Nyctophilus,
Otonycteris,
Pharotis,
Philetor,
Pipistrellus,
Plecotus,
Rhogeessa,
Scotoecus,
Scotomanes,
Scotophilus,
Tylonycteris,
Vespertilio. THE FERUNGULATA = THE CERTARTIODACTYLA ORDER UNNAMED FAMILY ZHELESTIDAE ORDER
ARCTOCYONIA+ Herbivore
that was sheep-sized, but it looked like a dog.
Its molars, however, were broad and adapted to crushing rather than
slicing flesh. Some were adapted to
climbing with muscular limbs and, possibly, a prehensile tail.
Paleocene Arctocyon ORDER
UNNAMED+ FAMILY
MESONYCHIDAE Carnivores.
Early forms were dog-like. Later,
they were quite large. This group
likely was related to the whales. Paleocene
to upper Eocene Mesonyx, Andrewsarchus ORDER ARTIODACTYLA These are the even-toed ungulates. SUBORDER
UNNAMED+ FAMILY
DICHOBUNIDAE The
basal artiodactyls. These animals
had multiple digits on the fore and hind feed (5 and 4, respectively), but they
bore the weight on digits 3 and 4, each of which terminated in a small hoof.
They had the diagnostic double pulley astragalus.
They also showed artiodactyls features in the skull.
Lower
Eocene to Oligocene Diacodexis SUBORDER SUIFORMES (BUNODONTIA) Generally, omnivores. The pigs and hippos are characterized by having bulbous cusps on their molars. Also, they have powerful canines. Upper Oligocene to the present FAMILY
ENTELODONTIDAE+ These
pig-like animals had long skulls. Omnvivores.
Oligocene Dinohyus FAMILY SUIDAE Pigs.
Formerly distributed through Upper Oligocene to present: Perchoerus+ Subfamily Babyrousinae (Babyrousa): Babyrousa. Subfamily Phachoerinae (Warthogs): Phacochoerus. Subfamily Suinae (Hogs and Pigs): Hylochoerus, Potamochoerus, Sus FAMILY TAYASSUIDAE Peccaries.
Omnivores of the southwestern US to Oligocene to present. Catagonus,
Pecari, Tayassu. FAMILY
ANTHRACOTHERIIDAE These
animals were sisters to the hippos. Small
at first but large later (the size of a pygmy hippo).
Eocene
to Pliocene FAMILY HIPPOPOTAMIDAE Hippopotamuses.
These animals ranged through all of sub-Saharan Middle Miocene to present Hippopotamus,
Hexaprotodon, Choeropsis+ SUBORDER SELENODONTIA These animals have specialized cheek teeth with a selenodont pattern (pairs of crescent moon ridges). Upper incisors reduced or missing (elongate as sabers in some for sexual display). Compound stomach. TYLOPODA FAMILY
MERYCOIDODONTIDAE Oreodonts.
These animals were pig-sized browsers that moved in large herds.
They had 4 toes on each foot. Merycoidodon,
Bathygenys FAMILY
PROTOCERATIDAE They
were deer-like in form, but with shorter legs.
They also evolved horns (as seen in the Ruminantia) above the eyes and on
the nose. Upper
Eocene to Pliocene. FAMILY CAMELIDAE Camels,
Llamas, Vicugna. Early camels had
two toes with hooves. Later, they
evolved pads. The center of origin
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