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Mammalogy, Adaptation, Diversity and Ecology

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This lab manual has been prepared specifically for use in the Mammalogy course taught at Northern Arizona University and is intended to be used in conjunction with the lecture text, Mammalogy, Adaptation, Diversity and Ecology by Feldhamer et al. The keys contained herein were prepared for use with the specimens in the NAU vertebrate collection, and do not include all species that can be found in Arizona, nor all families of the world. In making these keys, I relied heavily on Donald Hoffmeister’s Mammals of Arizona and DeBlase and Martin’s A Manual of Mammalogy. For more complete keys to species in Arizona or to families of the world, I refer students to these two excellent sources.

Using this manual – Throughout this manual I have used certain conventions that may seem confusing to the beginning student. In referring to teeth, I have used the capital letters I, C, P and M to represent incisors, canines, premolars and molars, respectively. Dental formulae are given for one side of the jaw only. The number of upper teeth of a particular type are given first and separated from the number of lower teeth of the same type with a “/”. For example, a skull with 3 upper incisors and 2 lower incisors on each side would be given as: I 3/2. If the number of teeth is variable, the range of teeth is given, separated by a “-“. For example, if a group of mammals are characterized by having 3 upper incisors and anywhere from 2-3 lower incisors depending upon the species, then this is given as I 3/2-3.


Throughout this course you will be responsible for knowing order, family, genus and species names. Recall that all mammalian families end in the suffix “idae” (pronounced “id ee’ ”). When mammalogists refer to an entire family of animals, they will use the family name without the “ae” ending. For example, if I want to refer to all members of the dog family, the Canidae, I would refer to them as “canids”. Likewise, all cats would be “felids” and all rodents of the family Heteromyidae could be called “heteromyids”. This is one reason it is important to know family names, mammalogists use these terms all the time and you will become baffled quickly if you don’t know them. Recall also that the species name is a combination of a noun (the genus) and a descriptor, usually an adjective (species epithet). Both parts are required for a correct scientific name, which makes sense given that the second half, the adjective, wouldn’t mean anything without the genus. For example, the scientific name of the black bear is Ursus americanus, Ursus meaning “bear”, americanus meaning “american”. The species name is NOT americanus alone. “American” what? It makes no sense alone, there are many “american” mammals. Recall also that the entire species name is italicized or underlined and that the genus is always capitalized but the descriptor is not.

Does spelling of these matter? An example will illustrate that it does:

Microtus californicus is a rodent, the California vole, while Macrotus californicus is a bat, the large-eared, leaf-nosed bat. One letter difference and I wouldn’t know whether to look for the animal under my feet or over my head. Note that both of these animals have the same descriptor “californicus” which means Californian. The question is, the Californian what? In the case of the vole, an animal with relatively small ears, the genus Microtus means “little ear”, so it’s the “californian little-ear”. What does Macrotus mean? Knowing the Greek and Latin roots for these terms can make remembering them much more interesting. I recommend the Dictionary of Word Roots and Combining Forms by Donald J. Borror.
DeBlase, A.F. and R.E. Martin. 1981. A Manual of Mammalogy, 2nd ed.. McGraw-Hill,

Boston, 436pp.

Hoffmeister, D.F. 1986. Mammals of Arizona. University of Arizona Press, Tucson, 602pp.

World Biogeographic Provinces.

Throughout this course, you will be asked to know mammalian Orders and Families of the world as well as more detailed information for North American and Arizona mammals. A critical part of this is knowledge of the geographic distribution of orders, families and species. Therefore, a fundamental understanding of world biogeographic provinces and the habitats and major landforms of Arizona are essential. Read pages 435-437 (1st edition) or 416-419 2nd edition) in your text for an introduction to major faunal regions of the world and label them on the world map below. I assume you are familiar with the major countries of the world (if you are not, review your geography!), but I have labeled some of those areas that may be less familiar and are important areas of mammalian diversity.

What biotic provinces are divided by Wallace’s line?

Mammalian Characteristics and Comparisons
Refer to the pages in your lecture text indicated for each section. You are responsible for all terms in bold face in the text and those labeled on Figures 1 and 2 of the lab text, as well as information on this page.

Review of Mammal Skeleton pp 69-72 (1st ed) 66-68 (2nd ed) in text, Basic Skeletal Patterns section

  1. Identify the teeth, bones, processes and foramina on the skulls provided. Use Fig 5.8 in your text and Fig 1 in lab manual. Recall: Process = projection off of bone, foramen = hole, fossa = indentation

  2. Test your knowledge of skull anatomy by identifying the major bones on the porpoise and deer skull.

  3. Review the major bones of the cat skeleton, noting the components of the axial and appendicular skeleton. Use Fig. 2 in lab manual. Test yourself by identifying bones from the disarticulated skeletons and the forelimbs of the porpoise and bat.

Compare the cat skull to that of the lizard. Which has a secondary palate and turbinates

and why?

  1. Look at the ear ossicles of the cat and/or human. Draw and label the mammalian ear ossicles in order from lateral to medial

Teeth: pp 55-59 (1st ed) 53-56 2nd ed) in text Tooth Structure, Tooth Replacement, Dental Formulae and Primitive Dental Formulae sections.

  1. Use the horse’s tooth to identify the major components of a mammalian tooth. Use Fig 4.17 in your text as a guide.

  2. Compare the teeth of the echidna (spiny anteater), porpoise and coyote. Which skulls show homodont dentition? Heterodont? Edentate? (Use text glossary for definitions of these terms)

  3. Label the incisors, canines , premolars and molars on Fig 1 of lab text.

  4. Compare the cusp patterns of the pig, the deer, and the elephant. Which terms describe each of these crown patterns or tooth types? Use Fig 4.18 in your lecture text and Figure 3 in lab text.

Pig _______________ Deer ______________________ Elephant __________________

  1. Describe the dental formula of the following skulls: opossum, cat, squirrel and porpoise. For what function are the various tooth types adapted? Which are missing and or modified? Which show the full complement based on primitive dental formulae?

Opossum _____________ Cat _____________ Squirrel ___________ Porpoise __________
Hair: pp 64-66 (1st ed)61-63 (2nd ed)in text, Hair section

  1. Compare the pelage on the fox and peccary (javelina) and note the presence and amount of guard hairs and fur. How might this affect the geographic distribution of these two animals? ________________________________________________________________________Where are vibrissae located? _______________________________________________

What is their function? ___________________________________________________

Which hairs give the animal its apparent color? ________________________________

2) Compare the coat colors of the woodrat and kangaroo rat. Which part of the body is darkest and lightest and why and what is the term for this color pattern? ________________________________________________________________________

Why would the pocket gopher lack this pattern?______________________________

3) Compare the two pocket mice. What would the substrate that these animals live on look

like and why?___________________________________________________________

4) Compare the adult and juvenile mice to see differences in pelage patterns and molt line

  1. Compare the weasel in summer and winter pelage

Figure 1. Coyote (Canis latrans) Skull

  1. angular process of the dentary 21) sagittal crest

  2. auditory (tympanic) bulla 22) nuchal crest

  3. condyle of the dentary 23) masseteric fossa

  4. coronoid process of the dentary 24) mandibular fossa

  5. dentary bone 25) post-orbital process

  6. external auditory meatus

  7. frontal bone

  8. infraorbital foramen

  9. interparietal bone

  10. jugal bone

  11. lacrimal bone

  12. maxillary bone (maxilla)

  13. occipital bone

  14. occipital condyle

  15. palatine bone

  16. parietal bone

  17. premaxillary bone (premaxilla)

  18. nasal

  19. squamosal bone

  20. zygomatic arch

Figure 2 Major bones of the cat skeleton.

  1. Atlas 11. Sternum 21. Metacarpals

  2. Axis 12. Rib 22. Phalanges

  3. Cervical vertebrae 13. 23. Femur

  4. Thoracic vertebrae 14 Scapula 24. Patella

  5. Lumbar vertebrae 15. 25. Tibia

  6. Caudal vertebrae 16. Humerus 26. Fibula

  7. Illium of pelvis 17. Olecranon process 27. Calcaneum

  8. Sacrum 18. Ulna 28. Tarsals

  9. Pubis of pelvis 19. Radius 29. Metatarsals

  10. Ischium of pelvis 20. Carpals 30. Clavicle

Note: there are no structures for #’s 13 and 15

Tooth descriptors commonly used in Mammalogy

Occlusal surface (cusp patterns) (Figure 3)
Bunodont – cusps are covered with enamel (unless heavily worn) and form rounded or pointed cusps

Selenodont – complex folds lead to crescent shaped-pools of softer dentine surrounded by enamel. Crescents (selenes) run parallel to the tooth row.

Lophodont – complex folds of enamel lead to complex pattern of pools of dentine and cement surrounded by enamel. Lophs (pools of dentine or cement) may be perpendicular to the tooth row or more complex, but not forming half-moon shapes (selenes). Patterns change as the tooth continues to wear.

Crown height (Figure 4 and 5)

Brachyodont – low crowned tooth. Viewed from the side, there is a constriction

where the tooth meets the bone. Mandible does not have to be deep to hold tooth

Hypsodont – high-crowned tooth. No constriction of the tooth where it meets the bone, tooth often forms a column protruding deeply into socket, resulting in deep mandible.

Growth (Figure 5)

Rooted teeth - these teeth often have roots that constrict to a point. Once the tooth reaches full size, the root canal constricts and growth ceases.
Ever-growing, rootless teeth – these teeth often have roots that do not constrict markedly to a point. The root canal remains open and the tooth continues growing throughout life. Often hypsodont with much of tooth in bone and therefore a deep mandible.
NOTE: These descriptors can be used in combination, e.g, a “brachyodont, bunodont tooth.”, but not a “selenodont, bunodont” tooth.

Bunodont (human) Selenodont (deer) Lophodont (elephant)

Figure 3. Cusp patterns of mammalian teeth. Cement = black, dentine = dots, enamel = white

Brachyodont Hypsodont

Worn Newly erupted

Figure 4. Crown height descriptors commonly used in mammalogy. Cement = black, dentine = dots, enamel = white
Dentary of deer Dentary of horse Dentary of rabbit

rooted rootless most of life rootless

brachyodont hypsodont hypsodont

Figure 5. Comparison of rooted and rootless (evergrowing) teeth in three mammal species.

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