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The Order Edentata
was established for placental mammals with reduced to absent dentitions.
Current research indicates that it is polyphyletic and comprised of two
widely separated placental mammal taxa: the Xenarthra for the anteaters, sloths and armadillos;
and the Pholidota for the pangolins, which are more
closely related to carnivorans such as dogs and cats.
Recent studies have divided the xenarthrans into two
related orders. The cingulates have a dermal bones in their skin, producing a
"shell." The pilosans are covered with hair.
anteaters, sloths and armadillos
- xenarthrous vertebrae
- incorporation of caudal vertebrae into sacrum [Fig.
- reduced to absent dentition, without enamel;
- low metabolic rates and low body temperatures
- Order CINGULATA
- Dasypodidae (9, 21) Armadillos
Glyptodontidae the extinct glyptodonts (Fig.
- Suborder Folivora (Tardigrada)
- Bradypodidae (1, 4) Three-toed sloths
- Megalonychidae (1, 2) Two-toed sloths
- Suborder Vermilingua
- Myrmecophagidae (2, 3) True anteaters
- Cyclopedidae (1,1) Silky anteater
- the two living sloths were traditionally placed in the same family
(Bradypodidae) because they have many
characteristics in common, such as the following:
- no tail, blocky skull
- arboreal; hang upside down in trees
- variable body temperature, bask to warm
- form symbiotic relationships with red or green algae on the surface
of hair making green appearance to pelage
- gestation unusually long--11.5 months
(three-toed tree sloths, ais) [Figs.
3 toes on front and hind limb [Fig. 10-15]
8 or 9 cervical vertebrae give neck greater flexibility
photographs of Bradypus
tridactylus left by Dr. Lloyd Glenn Ingles, California Academy of Sciences.
Copyright � 2001 California Academy of Sciences. Right by Ben
Hernandez, � 2001 used with permission
- feed on ants and termites (myrmecophagy)
- long tapered skull [Fig. 10-14]
- no teeth
- very long vermiform tongue [Fig. 10-14] extending to posterior portion of sternum
- large salivary glands
- powerful clawed forelimbs with 3 toes
[Fig. 10-11, 1012C]
- Neotropical, Nearctic
- body covered with bony
scutes, which are overlain by epidermal, keratinized scales, connected
by flexible skin, and are attached to body by connective tissue
- homodont dentition
- diet is insects, invertebrates, carrion, plant material
- powerful diggers
- delayed implantation
- birth of 1 to 12 young from a single ovum (monozygotic
produces four young of the same sex.
small mammal) has
expanded its range into the Southeastern and South
Central U.S since crossing the Rio Grande
in the late 1800s.
Dasypus novemcinctus -- nine
banded armadillo photograph � 2001by Dr. Allan H. Chaney,
Texas Small Mammal