Traditional view: Insectivorans represent primitiveeutherian stock.

Original classification of Insectivora (mid-1800s):

Elephant shrews

Treeshrews

Flying lemurs

Erinaceidae

Solenodontidae

Soricidae

Talpidae

Chrysochloridae

Tenrecidae

Insectivora

Original classification of Insectivora (1866):

Elephant shrews

Treeshrews

Flying lemurs

Erinaceidae

Solenodontidae

Soricidae

Talpidae

Chrysochloridae

Tenrecidae

Cecum present: Order Menotyphla

Cecum absent: Order Lipotyphla

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)

Proposed synapomorphies (Butler 1988):

1. Maxillary expansion in orbit2. Mobile proboscis3. Reduced jugal4. Hemochorial placenta5. Reduced pubic symphysis6. Cecum absent

Lipotyphla

Late 1900s: Is Lipotyphla a natural group?

1. Maxillary expansion in orbit (preventing contact of palatine & frontal)

maxilla

palatine

frontal

Hedgehog

Opossum

BUT, golden moles, some tenrecsdon't have expanded maxilla.

2. Mobile proboscis

present insome...

absent in others...and PRESENT inmany non-lipotyphlans

3. Reduced jugal

BUT, small jugals in hedgehogs mayrepresent ancestral condition ineutherians.

Jugal reduction in other lipotyphlansnot well understood.

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

shrews,some moles

some moles

5. Reduced pubic symphysis

connected with cartilage only; no bony fusion

ilium

pubis

BUT, reduced symphysis foundin most fossorial mammals.

"Reduced" difficult to categorize.

smallintestine

largeintestine

Cecum:

1st part of large intestine

2 primary functions:

1) Microbial breakdown of partiallydigested food

2) Recover moisture fromdigesting food

In general, faunivores have simplegut tubes (animal prey easier todigest).

Ancestral eutherian conditionuncertain.

Herbivore Carnivore Insectivoran

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

DNA sequence data:Lipotyphla is non-monophyletic!

Laurasia

Gondwana

Plate tectonics separate N. & S. supercontinents

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

Southern hemisphere radiation(‘Afrotheria’)

Northern hemisphere radiation(‘Laurasiatheria’)

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

Afrotheria Laurasiatheria

Laurasiatheria

Afrotheria

Parallel adaptive radiations on N. & S. supercontinents: