Eutherians:
As we've discussed several times, these are your true placental mammals.
Distinguished from the rest by much more complete development within the mother's body before birth.
(Placenta forms from “better” embryonic tissues).
Comment:
There have been a lot of changes here. This is particularly true for many of the animals that used to be classified as “Insectivora”, but also elsewhere.
It appears that the first six groups (3 in this set of notes) are related (or at least the latest DNA/cladistic analyses seem to show this).
Your text combines them in a clade called “Afrotheria”, which is in turn composed of two clades, each with three orders.
We'll just worry about the orders.
Order Afrosoricidae
Name loosely refers to “African” shrews, although they're not really related to shrews.
Two families:
Tenrecidae:
Tenrecs - generally small African mammals that superficially resemble shrews.
size range is shrew -> rabbit
In Madagascar underwent a spectacular radiation since they were isolated from most other areas.
Although same basic shape is similar, actually occupy a variety of niches.
Some of them are also spiny and can roll themselves into a ball when threatened.
Strangest animal is probably the otter shrew.
Looks and behaves like a miniature otter; found in west and central Africa.
Eats mostly invertebrates, but fish are also taken.
Has large whiskers to help it find food. Moves (swims) using lateral movement of tail.
Chrysochloridae:
Won't say too much about them - golden moles; look much like marsupial moles and behave much like our moles.
Can move underground surprisingly quickly (almost have a swimming motion if the soil is loose - see picture on p. 125).
Order Macroscelidae
Single family (Macroscelididae) with 16 species.
Used to be lumped in with the insectivores, but have been in their own group for quite some time now.
Most live in sub-Saharan Africa, with a single species found in North Africa.
Some controversy as to cause of the disjunct distribution.
Called elephant shrews due to their rather long nose.
Generally live along the ground (in all kind of habitats).
Eat invertebrates of all kinds, from those that live in litter and soil to ants and termites (depending on species).
Some can run remarkably fast (primary means of predator escape).
Some elephant shrews bask - book speculates this is to lower the cost of thermoregulation.
Unfortunately, many of them are now endangered (mostly habitat destruction and some hunting (presumably for the larger species - largest weighs about a pound)).
Order Tubulidentata - aardvarks.
Only one species (family Orycteropodidae)
“Aardvark” derives from the Afrikaner “earth-pig”.
Aardvarks are found in sub-Saharan Africa, and used to be quite common. Are still fairly common but numbers have shows a definite decline.
Not seen much since they're nocturnal.
Forage at night and return to their burrows by morning.
Fossil aardvarks were found in parts of Europe. Weigh up to 65kg (that's just over 140 pounds).
Very thick skin, sparsely haired (but not “naked”)
Exceptional sense of smell, and can close off opening to nose when digging.
Can break open termite mounds:
(These are extremely hard to break open).
Burrows of aardvarks are used by many other animals including wart hogs, monitor lizards, but many other animals as well.
Text comments that warthogs depend on aardvark burrows in parts of their range.
Eat mostly ants and termites, but also other insects they come across.
Have a long sticky tongue that helps them catch ants and termites.
Solitary, but seem to tolerate each other when they come across one another.
Interesting relationship with the cucurbit plant:
During the dry season will dig up the fruits (fruits are underground!).
Seeds are deposited with their feces.
(Text makes it appear that feces are buried, but this isn't totally clear).
Misc. comment:
Some thought that the Egyptian god “Seth” is based on an Aardvark.