Module 14: Age And Sex Assessment

Question 1

Teeth

Answer 1

Immature (deciduous)-often incomplete and there are fewer, smaller
-deciduous molars m1, m2, m3 replaced by permanent premolars P1-P4
Eruption in stages that are predictable

Question 2

Teeth pt 2

Answer 2

Shape and wear good indicator of age esp in ruminants-regional variation (diet), domestic animals much softer diet, significantly less wear
Carnivores tend to fx canines when older (mid-old age)
Carnivores/omnivores demonstrate gum line recession (gingival recession)
Cementum deposition can provide accurate est in SOME species
-laid down w ^ age, sometimes light and dark layers like trees, sometimes thickness speaks to age

Question 3

Skull aging

Answer 3

Suture closure useful sometimes, but poor health/castration can affect
Saggital and lamboidal crest increase in size with increased age
Postorbital constriction ^ and postorbital area narrows and zygoma widens in some species to allow for ^ muscle size
Postorbital process ^ in length w age, esp noticeable in domestic v feral cats

Question 4

Red fox suture study

Answer 4

BOBS (Basioccipital-basiospenoid) open 0-9mo, closed ~2yrs
PSBS (Presphenoid-basisphenoid suture) open 10-21mo, closed ~3yrs
PMMS (lateral palatal portion of premaxillary suture) open 34-57mo, partially fused 58-81mo (6-7y), closed 82+ mo (8+y)

Question 5

Epiphyseal fusion

Answer 5

Few studies in animals, not comprehensive like humans

Question 6

Horn/antler shape/size

Answer 6

Size and shape, ring count, # tines all age
Deer add tine each year
More than one method best when poss

Question 7

Sex assessment

Answer 7

Almost all species have sexual dimorphism-one sex bigger, sometimes subtle and castration often significantly reduces dimorphic features in males
Sex assessment of juveniles/subadults very hard to impossible due to lack of sexual development features
Very little on how to determine sex from skeleton in animal remains

Question 8

Sex

Answer 8

Presence of baculum in males-lack of one does not absolutely = female
Many species males dev. Horns/antlers while females don’t, but some species females do, just smaller
Male horses typically have canines while females do not, but they can, just 1-2 not all 4
Primates-males much larger canines than females

Question 9

Pelvis-artiodactyl

Answer 9

Males have tuberosity on inferior pubic ramus for attachment of the crura of the penis-lacking in females and castrated domestic males
Males have thicker (DV) and more robust pubic symphysis
Groove/ridge on superior edge of superior pubic ramus, more ventral in males, dorsal in females

Question 10

Metapodials

Answer 10

Sexual dimorphism noted in Bison

With the following measurements one can potential distinguish males from females.
• Transverse width at the mid-shaft (TWM)
• Transverse width at the distal end (bicondylar breadth (BB))
• Maximum length (ML)
• For the metacarpal, if:
—BB > 90- 1⁄2 (TWM/ML)x100- Male
—BB < 80- 1⁄2 (TWM/ML)x100- Female
• For the metatarsal, if:
—BB > 76.5- 1/3 (TWM/ML)x100- Male
—BB < 67.5- 1/3 (TWM/ML)x100- Female

Question 11

Turkeys

Answer 11

Males-metatarsal spur
Small portion of females are spurred
Male turkey long bones > females
Humerus: males 147-163mm, females 120-128mm
Femur: males 138-146mm, females 112-124mm