1 / 28

Claws, Nails, Hooves, Horns, and Antlers

Mammalogy (Fall 2013 Althoff - reference FDVM Chapters 6 & 20). LEC 14. Claws, Nails, Hooves, Horns, and Antlers. Claws, Hooves, & Nails. ______________ tissue Derived from “stratum germanitivum” layer of the _____________ (see Fig. 6.2, p98 - “stratum basale”)

miach
Download Presentation

Claws, Nails, Hooves, Horns, and Antlers

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Mammalogy (Fall 2013 Althoff - reference FDVM Chapters 6 & 20) LEC 14 Claws, Nails, Hooves, Horns, and Antlers

  2. Claws, Hooves, & Nails • ______________ tissue • Derived from “stratum germanitivum” layer of the _____________ (see Fig. 6.2, p98 - “stratum basale”) • In STRATUM BASALE, cells continuously divide and are pushed ____ by cells produced below them. Lack of ________________ from reduction of capillaries results in less metabolic activity

  3. FDVMK p98, Fig. 6.2 DERMIS

  4. Keratin • _________ produced by the epidermal cells • a “coiled” protein • ___________ • when mature, it is ________ tissue

  5. Claws • Most “_________” of keratinized structures • Occurs at the ______ of the digits • Grows _____________ • Consist of 2 parts: a) b) POLAR BEAR SIBERIAN TIGER

  6. UNGUIS--dorsal, scale-like plate; surrounds subunguis • SUBUNGUIS-- ventral

  7. Nails • Specialized “claws” • Found only among in ___________ • Facilitate better grip, more precise object manipulation by hands & feet • Only cover _________ surface • Co-evolved: __________________ _________________ in the dermis at the ends of digits of primates

  8. Hooves • Specialized “___________” • Found only among perissodactyls and artiodactyls • Unguis _______________ surrounds the subunguis • Adaptation combined with ___________ in number of digits • Constantly wears away slowly at ________ surface

  9. Basics....Generalities • Antlers are _________ annually • Horns are ___________ annually • Ungulates only ones with horns or antlers • Perissodactyls _________ have • Artiodactyls _______ have

  10. Perissodactyls • Examples: Horses, tapirs, rhinoceros • Exception: rhino “horn” is or ________ origin and lacks a bony core

  11. Rhino -- an exception (RHINOCEROTIDAE) • ____ bony core • ____ keratinized sheath • Keratinized fibers • ____ attached to bone “fused hairs”

  12. FDVMK p98, Fig. 6.2 DERMIS

  13. DERMAL PAPILLA--composed of blood and nerves which service follicle

  14. Artiodactyls • Two major groupings between ungulates showing major differences in “horns” vs. “antlers” Giraffidae vs. Cervidaevs. Bovidae/Antilocapridae

  15. Giraffe (GIRAFFIDAE) • Bony core (ossicone) • Hair-covered epidermis (skin) • Fused to cranium

  16. Giraffe OSSICONES

  17. Deer, Elk, Moose (CERVIDAE)

  18. Cervids - ANTLERS • Made of _______ • Usually ____________ • Supported on “___________” -- raised extension of _________ bone • ___________ …exceptions: a) caribou (reindeer)--both sexes b) Chinese water deer--none • Velvet--________, highly ____________ skin.

  19. Cervids - ANTLERS…con’t • Aside from __________ tissue, fastest growing tissue known • Antler size and number of tines function of: a) b) c) • Shed ___________ • ____________ antlers: caribou, moose, fallow deer

  20. Pronghorn (ANTILOCAPRIDAE) The “__________” when it comes to horns & antlers

  21. Pronghorn (ANTILOCAPRIDAE)

  22. Pronghorns - “Unique” Horns • _______ core covered by ___________ sheath • “Horn” sheath shed annually, new one grows ______________ • Males have, most females have but they are smaller • Upright horns with ______________ and short, anterior branch (prong) • ______ N. American ungulate with this type of horn

  23. Bison, Gazelle, Oryx, Water Buffalo (Bovidae) Grant’s gazelle

  24. Sichuan takin fringe-eared oryx springbok

  25. Marco Polo Sheep …subspecies of ________which is 1 of 2 thought to be the ancestor/origin of domestic sheep (the other is early mouflon) Kyrgyzstan CHINA Tajikistan Afghanistan Pakistan

  26. Bovids - Typical Horns • Bony core with _________________ • “Horn” sheath over this bony core • “Horn” sheath __________________ shed • Males have, females of some species have • __________________

  27. Bovids: HORNS...con’t • Horns are never branched • Horns are typically long & gracefully curved • Bighorn sheep, Mt. Goats, Bison, cattle in N. America….many, many species in Africa & Eurasia (Fig. 20.24, p400)

  28. Functions of Horns & Antlers • _______________: Show dominance among males and fight for mates, territory during “rut.” Therefore, selection “for” larger, more massive head “ornaments” • ______________: challenge conspecifics, ward off predators

More Related