What is an insectivora?. Insectivora Macroscelidea (elephant shrew), Scandentia,(tree shrew) Dermoptera (flying lemurs) Primitive group: 130 mya.

Presentation on theme: "What is an insectivora?. Insectivora Macroscelidea (elephant shrew), Scandentia,(tree shrew) Dermoptera (flying lemurs) Primitive group: 130 mya."— Presentation transcript:

1 What is an insectivora?

2 Insectivora Macroscelidea (elephant shrew), Scandentia,(tree shrew) Dermoptera (flying lemurs) Primitive group: 130 mya

3 Insectivores n Insectivores are considered to be "primitive" mammals n Smooth brain:_not as intelligent??? n Insectivores are named after their tendency to eat insects or invertebrates Does size matter?

4 Insectivora: Reference Page n Erinaceidae: hedgehogs n Tenrecidae: tenrecs and otter shrews. n Soricidae: shrews n Chrysochloridae: golden moles. n Solenodontidae: solenodons. n Talpidae: moles and desmans. There are 419 species in 6 families :

5 Insectivora: Morphology n Generally small. n Rostrum (snout) tends to be long. n Fur often consists only of guard hair (modified in some forms as spines). n Small braincase n excellent sense of smell and touch, but have poor senses of sight and hearing.

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

7 Insectivora’s are not Rodents: Why:_____________________

8 Insectivora: Fossil History Earliest insectivores date to the mid- Cretaceous (100MYA) Recognizable soricids and talpids date to the Eocene (50MYA). No Big Changes from ancient to now: Why? ____________________________________

9 Erinaceidae n 7 genera and 21 species. n Hedgehogs have barbless spines. n Hedgehogs are nocturnal and mainly terrestrial, or semi-arboreal. n They are omnivorous - invertebrates, eggs, fruit, carrion.

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11 Erinaceidae n Spines in hedgehogs are soft at birth, and harden a few weeks after birth. n In a defensive posture, the animal rolls up in a ball, using a band of muscles.

12 Erinaceidae n Hedgehogs also rub saliva over their spines. Interestingly, there are reports of hedgehogs killing toads, to produce ‘venemous spines.’

13 Talpidae: Moles n 17 genera and 42 species, distributed throughout Europe, Asia, Japan, and North America. n http://www.youtube.com/watch?v=4rAk4 pE0Vuw&safety_mode=true&persist_sa fety_mode=1 http://www.youtube.com/watch?v=4rAk4 pE0Vuw&safety_mode=true&persist_sa fety_mode=1

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

15 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.htmlhttp://www.arkive.org/russian- desman/desmana-moschata/video-05.html

16 Tenrecidae n Tenrecs are found in Madagascar only (this is bad news). Otter shrews found in west-central Africa.

17 Tenrecidae n Otter shrews (not surprisingly) look a lot like otters and are actually quite large. n Some Tenrecs can hibernate, and most have relatively low body temperatures. n The common Tenrec has as many as 32 offspring in a single litter!

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

19 Chrysochloridae: Golden Moles n They push soil w/ the snout, then push soil under the body with the limbs. n Claw on 3rd digit is enlarged.

20 Solenodontidae n 2 species. 1 restricted to Cuba, the other to Haiti and the Dominican Republic (this is not good news).Why?___________________ _____________________________ n Look like a cross between a rat and a shrew. n Omnivorous.

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

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

24 Soricidae n Smallest shrews are pygmy shrew while largest is House Shrew n Most have short legs. n 2 forms have webbed feet. n Small eyes, pointed rostrum, short dark fur.

25 Soricidae n Some use high frequency sound for communication, orientation, and prey detection. (Like bats) n Short lived: one year. n Often associated w/ moist habitats. n Some Shrews are poisonous.

26 Macroscelidae: Elephant shrews (not a real shrew) n 4 genera and 15 species of elephant shrews. n Central and eastern Africa. n Insectivores to omnivores. n Can move bipedally. n Long, flexible snout, large eyes and long ears.

27 Elephant shrew video

28 Scandentia: Tree Shrews n Have long been considered primates..

29 Scandentia: Tupaiidae n Restricted to Asia. n Mostly diurnal and omnivorous. n Not all are arboreal, and they are not shrews. n Most scent mark. n Resemble squirrels in general morphology.

30 Dermoptera n These are the ‘flying lemurs’ or Colugos. n In the past, they have been classified with bats, primates, and insectivores.

31 Dermoptera n They weigh up to 2kg, and can glide at up to 25m/s which is very fast for a glider.

32 Use your notes to identify the following groups Only one from each group: (use your reference page) n 1. ______ n 2.______ n 3. _______ n ( hint not an elephant shrew) 4.________ 5. ________ 6.________

33 Work in groups of two: n A. List 5 unique characteristics of insectivora n B. List 5 similarities that insectivora share with other mammals. n C. List 5 examples of insectivora n D. Explain in 2-3 sentences, why it is believed that insectivora animals are “primitive” Do you think they are primitive?