Mammalogy Lab 1: Cranial & Postcranial anatomy

Foramen

hole in bone where vessels pass through

Fissure

hole in bone larger than foramen

Canal

narrow tubular passage or channel

Meatus

opening into a canal

Fenestra

many small holes in a region of bone

Fossa

depression in bone (usually site of muscle attachment)

Process

bony projection

Condyle

process on one bone that articulates with another bone

Bulla

bones that cover middle ear ossicles

What are the two major differences between placental versus marsupial skulls?

1. Marsupial skulls have palatine vacuities

2. The angular process of marsupial dentary bones are inflected medially

Homodont

One type of tooth

ex: dolphins

Heterodont

more than 1 kind of tooth

Diphyodont

2 sets of teeth within a lifetime (deciduous/milk teeth and adult teeth)

Hypsodont

high crowned with shallow roots

Brachyodont

short crowned, deep roots

ex: humans

Lingual

toward the tongue

labial

toward lip or cheek

Cusp & Loph

cusp-sharp projection on a tooth

loph- ridge between two cusp

to occlude

to close the teeth

Occlusal surface vs occlusal pattern

surface- working surface of the teeth

pattern- way teeth mesh together

4 basic tooth types of mammals

Incisors, canines, premolars, molars

Tooth anatomy (4 parts)

1. Crown: covered in enamel

2. Dentin

3. Pulp

4. Cementum: surrounds roots

why are teeth important in mammalogy?

1. useful for identification

2. teeth fossilize well

3. teeth tell us species relationship, diet, health, age, size

Tribosphenic molars

3 cusps, insectivores

Quadrate molars

4 cusps, omnivores

zalambdodont

zalambdodont

v-shaped

apex of lingual ridge is protocone

medial ridge is paracone

insectivores

Dilambdodont

Dilambdodont

most insectivores

forms a w shape ridge called ectoloph from the paracone and metacone

protocone may form w shaped when hypocone is well developed, or a v shaped if not developed.

Selenodont

Selenodont

-most seen in artiodactyls (ungulates)

-herbivores

-anterior-posterior expansion of cusps into crescent shaped ridges

Bunodont

Bunodont

-crown is low rounded cusps

-omnivores

EX: pigs, primates, racoons, bears

Lophodont

Lophodont

• Order Perissodactyla (horse, rhinos, tapirs)

• herbivores

• cusps fuse to form long ridges aka lophs

Loxodont

Loxodont

• extreme lophodonty

• sloping teeth

• browsing diet

• washboard shaped

• EX: elephant, capybara

Carnassial pair

last upper premolar and first lower molar p4/m1

• order Carnivora

Rodent teeth

• incisors specialized for gnawing

• molar patterns may be simple or complex

• incisors enamel is pigmented (yellow/orange) and confined to anterior border of tooth

mammal integument structure

1. Medulla

2. Cortex

3. Cuticle

Cortex

elongated cells that may contain pigment granules

Medulla

loosely arranged cells forming the core of hair shaft

Cuticle

what is it? what is coronal vs imbricate

cuticle is the outer sheath composed of keratinous scales

Coronal: scales completely encircle hair shaft (simple, serrate, or dentate edges)

Imbricate: scales don’t encircle shaft but overlap

Condyloid process

small openings in hard palate

palatine foramina

Loxodont

lophodont

dilambdodont

selenodont

zalambdodont

lophodont