What is an insectivora?

What is an insectivora?

Insectivora

Macroscelidea (elephant shrew), Scandentia,(tree shrew) Dermoptera (flying lemurs)

Primitive group:

130 mya

Insectivores Insectivores are

considered to be "primitive" mammals

Smooth brain:_not as intelligent???

Insectivores are named after their tendency to eat insects or invertebrates

Does size matter?

Insectivora: Reference Page

Erinaceidae: hedgehogs

Tenrecidae: tenrecs and otter shrews.

Soricidae: shrews

Chrysochloridae: golden moles.

Solenodontidae: solenodons.

Talpidae: moles and desmans.

There are 419 species in 6 families:

Insectivora: Morphology Generally small. Rostrum (snout) tends to

be long. Fur often consists only of

guard hair (modified in some forms as spines).

Small braincase excellent sense of smell

and touch, but have poor senses of sight and hearing.

Teeth are rooted, so do not grow throughout life. Anatomy defines species. Ex. some species are open rooted teeth, grow throughout life

Insectivora’s are not Rodents: Why:_____________________

Insectivora: Fossil HistoryEarliest insectivores date to the

mid-Cretaceous (100MYA)

Recognizable soricids and talpids date to the Eocene (50MYA).

No Big Changes from ancient to now: Why?____________________________________

Erinaceidae

7 genera and 21 species. Hedgehogs have barbless spines. Hedgehogs are nocturnal and mainly

terrestrial, or semi-arboreal. They are omnivorous - invertebrates, eggs,

fruit, carrion.

Erinaceidae Spines in hedgehogs

are soft at birth, and harden a few weeks after birth.

In a defensive posture, the animal rolls up in a ball, using a band of muscles.

Erinaceidae Hedgehogs also rub saliva over their

spines. Interestingly, there are reports of hedgehogs killing toads, to produce ‘venemous spines.’

Talpidae: Moles 17 genera and 42 species, distributed

throughout Europe, Asia, Japan, and North America.

http://www.youtube.com/watch?v=4rAk4pE0Vuw&safety_mode=true&persist_safety_mode=1

Extreme modification of the pectoral girdle - including rotation of the fore-feet.

Talpidae: Desmans– Eat aquatic invertebrates and fish– Some species have long, laterally

compressed tails.– Some evidence that they use echolocation to

locate prey.– http://www.arkive.org/russian-desman/

desmana-moschata/video-05.html

Tenrecidae Tenrecs are found in Madagascar only

(this is bad news). Otter shrews found in west-central Africa.

Tenrecidae Otter shrews (not surprisingly) look a lot

like otters and are actually quite large. Some Tenrecs can hibernate, and most

have relatively low body temperatures. The common Tenrec has as many as

32 offspring in a single litter!

Chrysochloridae: Golden Moles Found in central and southern Africa. They have iridescent fur. Vestigal eyes.

Chrysochloridae: Golden Moles They push soil w/ the snout, then push

soil under the body with the limbs. Claw on 3rd digit is enlarged.

Solenodontidae 2 species. 1 restricted to Cuba, the

other to Haiti and the Dominican Republic (this is not good news).Why?___________________ _____________________________

Look like a cross between a rat and a shrew.

Omnivorous.

Solenodontidae

Submaxillary glands produce toxic saliva, which flows into the bite via grooved 2nd incisor.

Soricidae: Shrews 23 genera and 312 species. Generally small (3g - 100g). Organized into 2 subfamilies: ‘red-toothed’

shrews and the ‘white-toothed’ shrews.

Soricidae Smallest shrews are

pygmy shrew while largest is House Shrew

Most have short legs. 2 forms have webbed

feet. Small eyes, pointed

rostrum, short dark fur.

Soricidae Some use high frequency sound for

communication, orientation, and prey detection. (Like bats)

Short lived: one year. Often associated w/ moist habitats. Some Shrews are poisonous.

Macroscelidae: Elephant shrews (not a real shrew) 4 genera and 15 species

of elephant shrews. Central and eastern

Africa. Insectivores to

omnivores. Can move bipedally. Long, flexible snout,

large eyes and long ears.

Elephant shrew video

Scandentia: Tree Shrews Have long been considered primates..

Scandentia: Tupaiidae Restricted to Asia. Mostly diurnal and omnivorous. Not all are arboreal, and they are not

shrews. Most scent mark. Resemble squirrels in general

morphology.

Dermoptera These are the ‘flying lemurs’ or Colugos. In the past, they have been classified

with bats, primates, and insectivores.

Dermoptera They weigh up to 2kg, and can glide at

up to 25m/s which is very fast for a glider.

Use your notes to identify the following groups Only one from each group: (use your reference page) 1. ______

2.______

3. _______

(hint not an elephant shrew)

4.________

5. ________

6.________

Work in groups of two:

A. List 5 unique characteristics of insectivora

B. List 5 similarities that insectivora share with other mammals.

C. List 5 examples of insectivora D. Explain in 2-3 sentences, why it is

believed that insectivora animals are “primitive” Do you think they are primitive?