ZOO 4910 Lecture Notes - Giraffidae, Deer, Bovidae
2 May 2018
School
Department
Course
Professor
Bovid families
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Living bone inside sheath
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Keratin covered
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Fused to skull with connective tissue
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Present on males and some females
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Grow throughout life
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Horns:
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Only in cervids (deer, moose, elk)
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One single bone (no keratin layer)
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Velvet covered until mature
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Stimulated annually by hormones
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Sexually selected, only in males
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Shed annually
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Antlers:
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Presence of bone may or may not be fused to
body
Epidermis may persist, be temporary or never
be present
Some are covered in keratin
*see slide -structure of headgear
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No hair or fuzz (epidermis) on horns
Fused to bone
Cervidae
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Keratin -epidermis and fuzz -bone
Not fused
Bovidae
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Covered by epidermis (no keratin)
Not fused
Giraffidae (ocitones?)
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Fused
Keratin -epidermis -bone
Antilcapridae (prong horns)
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Ontogeny:
•
Phylogeny:
•
Physical Weapons: Headgear
Physical and Chemical Weaponry
Friday,*November* 24,*2017
12:28*PM
find more resources at oneclass.com
find more resources at oneclass.com
One of the smallest ungulates, does not grow
antlers
Mouse deer:
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Lacks antlers as well
Musk deer:
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Mouse deer is basal species
Headgear has independently evolved four times
in a unique way (intermediate species)
Morphological phylogeny: 4 independent origins
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1origin and one loss
More parsimonious explanation
Evolved once following mouse deer
divergence, and was loss in musk deer
divergence
Molecular phylogeny:
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Phylogeny:
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Most vertebrates have undifferentiated teeth
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Most mammals and few other groups (dinosaurs) display
differentiated teeth (heterodont dentition)
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Tusks = modified canine teeth
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--> diversity and disparity
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In mammals, teeth are specialized as incisors, canines,
premolars, and molars
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Opisthoglyphous: posterior, fixed
Proteroglyphous: anterior, fixed
Solenoglyhous: anterior, hinged
Canal hold venom gland
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Have to chomp on prey to insert venom
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Increase in complexity
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Most complex
Can be longer
Hinged fangs: spring out when mouth is
opened
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*see cross section of fangs
Teeth can be used to deliver chemical weapons
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Ingested/passively encountered
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Possibly collected in specialized
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Poisons:
Poisons vs Venoms:
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Venom:
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Physical Weapons: teeth
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find more resources at oneclass.com
Possibly collected in specialized
structured
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No specialized mechanism of delivery to
recipient
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Typically a single molecular entity or
compound with specific action
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Housed and produced in specialized
structures
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Associated with delivery device
(morphological convergence)
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Active delivery to recipient
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Typically multipart blend of compounds
with complex effects
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Venoms:
Snake fangs have large diversity and disparity
in terms of complexity
Causes gland to compress and
release venom when snake strikes
prey
Venom gland is located in cheek pouch
which is surrounded by compressor
muscle
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The venom gland pushes venom into the
secondary venom duct and the venom
moves down the venom canal within the
fang for release
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Structure:
Synthesis and Delivery:
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Regulation co-opted from pancreatic functions
Massive expansion of toxin genes via gene
duplication
To increase diversity of toxins within
each individual "cocktails"
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Other compounds are being included in
venom to at synergistically with other
toxins
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Positive selection = neofunctionalization
--> response in prey evolution
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*understanding diversity of snake venom
can help understand arms race between
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Diversity as a result of coevolutionary arms
race
Sequencing the genome of King Cobra venom:
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find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Presence of bone may or may not be fused to body. Epidermis may persist, be temporary or never be present. One of the smallest ungulates, does not grow antlers. Headgear has independently evolved four times in a unique way (intermediate species) Evolved once following mouse deer divergence, and was loss in musk deer divergence. Most mammals and few other groups (dinosaurs) display differentiated teeth (heterodont dentition) In mammals, teeth are specialized as incisors, canines, premolars, and molars. Teeth can be used to deliver chemical weapons. Have to chomp on prey to insert venom. Hinged fangs: spring out when mouth is opened. Typically a single molecular entity or compound with specific action. Typically multipart blend of compounds with complex effects. Snake fangs have large diversity and disparity in terms of complexity. Venom gland is located in cheek pouch which is surrounded by compressor muscle. Causes gland to compress and release venom when snake strikes prey.
