Traditional view: Insectivorans represent primitive eutherian stock.

1. Traditional view: Insectivorans represent primitive eutherian stock.

2. Original classification of Insectivora (mid-1800s): Elephant shrews Treeshrews Flying lemurs Erinaceidae Solenodontidae Soricidae Talpidae Chrysochloridae Tenrecidae Insectivora

3. Original classification of Insectivora (1866): Elephant shrews Treeshrews Flying lemurs Erinaceidae Solenodontidae Soricidae Talpidae Chrysochloridae Tenrecidae Cecum present: Order Menotyphla Cecum absent: Order Lipotyphla

4. Original classification of Insectivora (1900s): Elephant shrews: Order Macroscelidea Treeshrews: Order Scandentia Flying lemurs: Order Dermoptera Erinaceidae Solenodontidae Soricidae Talpidae Chrysochloridae Tenrecidae Cecum absent: Order Lipotyphla (but use of “Insectivora” continued)

5. Late 1900s: Is Lipotyphla a natural group? Lipotyphla Proposed synapomorphies (Butler 1988): Maxillary expansion in orbit Mobile proboscis Reduced jugal Hemochorial placenta Reduced pubic symphysis Cecum absent

6. Maxillary expansion in orbit (preventing contact of palatine & frontal) frontal maxilla palatine BUT, golden moles, some tenrecs don't have expanded maxilla. Hedgehog Opossum

7. 2. Mobile proboscis present in some... absent in others... and PRESENT in many non-lipotyphlans

8. 3. Reduced jugal BUT, small jugals in hedgehogs may represent ancestral condition in eutherians. Jugal reduction in other lipotyphlans not well understood.

9. some moles shrews, some moles Tenrecs, golden moles, hedgehogs, solenodons (& some primates, bats, rodents...)

10. 5. Reduced pubic symphysis BUT, reduced symphysis found in most fossorial mammals. "Reduced" difficult to categorize. ilium pubis connected with cartilage only; no bony fusion

11. Cecum: 1st part of large intestine 2 primary functions: Microbial breakdown of partially digested food Recover moisture from digesting food In general, faunivores have simple gut tubes (animal prey easier to digest). Ancestral eutherian condition uncertain. small intestine large intestine

12. Herbivore Carnivore Insectivoran

13. DNA sequence data: Lipotyphla is non-monophyletic! Whales & dolphins Artiodactyls Artiodactyls Carnivorans Pangolins Perissodactyls Bats Solenodons Moles Shrews Hedgehogs Primates Treeshrews Colugos Lagomorphs Rodents Xenarthrans Golden moles Tenrecs Elephant shrews Aardvarks Dugongs & manatees Hyraxes Elephants

14. Plate tectonics separate N. & S. supercontinents Laurasia Gondwana

15. Whales & dolphins Artiodactyls Artiodactyls Northern hemisphere radiation (‘Laurasiatheria’) Carnivorans Pangolins Perissodactyls Bats Solenodons Moles Shrews Hedgehogs Primates Treeshrews Colugos Lagomorphs Rodents Xenarthrans Golden moles Tenrecs Elephant shrews Southern hemisphere radiation (‘Afrotheria’) Aardvarks Dugongs & manatees Hyraxes Elephants

16. Parallel adaptive radiations on N. & S. supercontinents: Afrotheria Laurasiatheria Whales & dolphins Artiodactyls Artiodactyls Carnivorans Pangolins Perissodactyls Bats Solenodons Laurasiatheria Moles Shrews Hedgehogs Primates Treeshrews Colugos Lagomorphs Rodents Xenarthrans Golden moles Tenrecs Elephant shrews Afrotheria Aardvarks Dugongs & manatees Hyraxes Elephants