Skins and skulls of xenarthra, carnivora, perissodactyla, and artiodactyla



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LAB #7
SKINS AND SKULLS OF XENARTHRA, CARNIVORA, PERISSODACTYLA, AND ARTIODACTYLA
In this lab, you will learn to identify the skins and skulls of the mammals listed below. You also will be responsible for both scientific and common names during a quiz at the end of the lab period. I will provide characteristics for the skins and the skulls but you can also see the STUDY AID FOR SKULLS given below to find the distinguishing characteristics of the skulls. You should work on these characteristics PRIOR TO the lab period.
SKINS

Dasypus novemcinctus

Canis latrans

Vulpes vulpes

Vulpes velox

Urocyon cinereoargenteus

Procyon lotor

Taxidea taxus

Mephitis mephitis

Lynx rufus

Odocoileus virginianus

Odocoileus hemionus

Bison bison
SKULLS

Dasypus novemcinctus

Canis latrans

Canis lupus

Vulpes vulpes

Vulpes velox

Urocyon cinereoargenteus

Ursus americanus

Ursus arctos

Procyon lotor

Bassariscus astutus

Mustela vison

Lontra canadensis

Taxidea taxus

Mephitis mephitis

Puma concolor

Lynx rufus

Odocoileus hemionus

Odocoileus virginianus

Antilocapra americana

Bison bison
INTRODUCED SPECIES

Equus caballus

Bos taurus
STUDY AID FOR SKULLS
ORDER XENARTHRA
Dasypodidae
Dasypus novemcinctus (nine banded armadillo)

1. narrow tubular rostrum

2. uniform peg like teeth with no enamel

3. teeth not present in anterior part of jaws

4. 28 36 teeth (DF = 0/0, 0/0, 7 9/7 9)

ORDER CARNIVORA


Canidae rostrum elongate and narrow, enlarged canines, well developed carnassials (first lower molar, last upper premolar), 42 teeth (DF = 3/3, 1/1, 4/4, 2/3)
Canis latrans (coyote)

1. postorbital process thickened convex dorsally

2. elongate rostrum

3. ventral border of dentary without step


Canis lupus (gray wolf)

  1. similar to C. latrans but larger, heavier

  2. pronounced frontal more convex than C. latrans


Vulpes vulpes (red fox)

1. temporal ridges converge to form "v" shape

2. depressions on postorbital processes

3. total length less than 160 mm

4. ventral border of dentary without step
Vulpes velox (swift fox)

1. temporal ridges bow out laterally half way back

2. depressions on postorbital processes

3. first two incisors in straight horizontal line; third farther back

4. total length less than 160 mm
Urocyon cinereoargenteus (gray fox)

1. temporal ridges converge to form "u" shape

2. deep depressions on postorbital process

3. length of skull approximately 130 mm

4. ventral border of dentary with prominent step
Ursidae enlarged canines, no well developed carnassial pair, skull is more cat-like

than dog-like (rostrum is short), 42 teeth (DF = 3/3, 1/1, 4/4, 2/3)


Ursus americanus (black bear)

1. molars with flat, broad crown

2. diastema on lower jaw

3. hard palate extends beyond molars


Ursus arctos (grizzly bear)

1. similar to Ursus americanus but larger

2. prominent sagittal crest
Procyonidae 40 teeth, molars 2/2, carnassials not well developed except in Bassariscus
Procyon lotor (raccoon)

1. poorly developed carnassials

2. molars broad, canines round

3. palate extends beyond last molars



  1. skull rounded on upper surface


Bassariscus astutus (ringtail)

  1. palate terminates just posterior to last molar

  1. upper molars transversely elongated, much broader than long

  2. greatest length of skull is 77.2 mm

  3. postorbital process generally more pronounced than in Procyon

Mustelidae teeth 38 or less, molars 1/2, enlarged canine, short rostrum, carnassial pair


Mustela frenata (long tailed weasel)

1. palate extends beyond last molar

2. total length of skull less than 55 mm

3. inflated auditory bullae

4. postorbital processes pointed

5. upper molar dumbbell shaped

6. braincase is elongated

7. upper surface of skull is flat

8. 34 teeth (DF = 3/3, 1/1, 3/3, 1/2)
Mustela nivalis (least weasel)

1. similar to Mustela frenata except smaller

2. total length of skull less than 35 mm
Mustela vison (mink)

1. total length greater than 55 mm

2. blunt postorbital processes

3. upper molar dumbbell shaped

4. inflated auditory bullae

5. 34 teeth (DF = 3/3, 1/1, 3/3, 1/2)


Taxidea taxus (badger)

1. skull triangular in shape, broadest posteriorly

2. prominent sagittal crest and lambdoidal crest

3. last two molars triangular in shape

4. palate extends beyond molars

5. obviously inflated auditory bullae



  1. 34 teeth (DF = 3/3, 1/1, 3/3, 1/2)


Lontra canadensis

  1. postorbital process well developed

  2. infraorbital foramen large and roughly oblong

  3. auditory bullae not inflated

Mephitidae- molars 1/2, palate does not extend beyond last molar, carnassial pair, short rostrum


Mephitis mephitis (striped skunk)

  1. palate not extended beyond last molar

  2. auditory bullae concave

  3. frontal bone rounded, skull convex above

  4. mastoid region not inflated

  5. notch in lower posterior edge of dentary

  6. last molar not dumbbell shaped

  7. prominent sagittal crest

  8. 34 teeth (DF = 3/3, 1/1, 3/3, 1/2)


Spilogale putorius (eastern spotted skunk)

1. palate not extended beyond last molar

2. frontal bone flattened

3. mastoid region inflated; inflated appearance to braincase

4. auditory bullae convex

5. total length less than 60 mm

6. prominent sagittal crest

7. last molar not dumbbell shaped

8. ventral edge of dentary without notch at posterior end

9. 34 teeth (DF = 3/3, 1/1, 3/3, 1/2)


Felidae teeth 30 or less, rounded skull, short, blunt rostrum, upper molar small, long canines
Puma concolor (mountain lion)

  1. 4 upper cheek teeth each side

  2. robust skull

  1. 30 teeth (3/3, 1/1, 3/2, 1/1)


Lynx rufus (bobcat)

  1. 3 upper cheek teeth each side

  2. 28 teeth (3/3, 1/1, 2/2, 1/1)

ORDER ARTIODACTYLA


Cervidae lacrimal separated from nasal by antorbital fossa, no permanent horn cores, incisors absent above
Cervus elaphus (wapiti)

1. upper canines present

2. double lacrimal orifice

3. selenodont cheek teeth

4. rostral fenestrations

5. lacrimal depression anterior to eye

6. nasals proportionately longer than premaxillaries

7. frontal region only moderately depressed

8. 34 teeth (0/3, 1/1, 3/3, 3/3)
Odocoileus hemionus (mule deer)


  1. deep lacrimal fossa

  2. upper canines absent

3. in males, dichotomously branching antlers

  1. 32 teeth (0/3, 0/1, 3/3, 3/3)


Odocoileus virginianus (white tailed deer)

  1. shallow lacrimal fossa

  2. upper canines absent

3. in males, antlers with one main beam and tines branching dorsally

4. 32 teeth (0/3, 0/1, 3/3, 3/3)


Antilocapridae lacrimal separated from nasal by antorbital fossa, permanent horn

cores in both sexes, erect and bladelike, incisors absent in upper jaw


Antilocapra americana (pronghorn)

  1. deciduous horns with bony core persistant in both sexes

  2. horn sheath with one branch (prong) in males and no branches in females

  3. frontal foramina

  4. depression between protruding orbits

  5. 32 teeth (0/3, 0/1, 3/3, 3/3)

Bovidae-one lacrimal foramen on or just within anterior orbital rim; heard ornamentation consisting of permanent bony cores surrounded by permanent horny sheaths


Bison bison (bison)

  1. frontals expand laterally behind orbits

  2. zygomata not visible from above

  3. premaxillae not in contact with nasals

  4. 32 teeth (0/3, 0/1, 3/3, 3/3)

INTRODUCED SPECIES


ORDER ARTIODACTYLA
Bovidae-one lacrimal foramen on or just within anterior orbital rim; heard ornamentation consisting of permanent bony cores surrounded by permanent horny sheaths
Bos taurus (cattle)

  1. frontals not expanded laterally behind orbits

  2. zygomatic arch visible from above

  3. premaxillae in contact with nasals

  4. 32 teeth (0/3, 0/1, 3/3, 3/3)

ORDER PERISSODACTYLA


Equidae-elongate, heavy skull with rectangular, high-crowned (hypsodont) molars
Equus caballus (horse)

  1. canines not present in mares and geldings (present in stallions)

  2. molars rectangular in shape

  3. lower canines not crowded forward with incisors

  4. P1 usually visible, but P1 rarely emerges from lower jaw

  5. 36 teeth (3/3, 0/0, 3/3, 3/3)



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