150 likes | 253 Views
The adaptive significance of hooves in Ungulates. Eyerusalem. What are ungulates?. Mammals with hoofs mostly eat plants Spend ¾ of their time by eating and 80 hours digesting each meal. What is hoof?. A hoof is a modified toenail composed of two structures
E N D
What are ungulates? • Mammals with hoofs • mostly eat plants • Spend ¾ of their time by eating and • 80 hours digesting each meal
What is hoof? • A hoof is a modified toenail • composed of two structures • the unguis (a scale- like plate) • sub unguis ( softer layer) • Hooves are the principal point of contact between the legs and the ground as a result ungulates are said to have unguligrade limbs
What is hoof? Rhinoceros Zebra Warthog Wildebeest
evolution of ungulates • From one ancestor • Evolved to eat tough plants and • Flee from fierce predators • The first species was up running 60 million years a go. • Since then, a huge diversity of ungulates have come and gone. • Today there are 207 different species
The two major orders of ungulates • Artiodactyls (even-toed ungulates) • Perissodactyla (odd-toed ungulates) • Artiodactyls: • the most successful group of large herbivores on earth to day • Contains the majority of domesticated mammal. • approximately 240 ungulate members of this order show incredible diversity in size, form dietary preference, and climatic tolerance. • The primary distinguishing feature of all the ungulates within this order is the paraxonic limb structure in which the symmetry of the foot passes between the two middle digits(3&4) • Paraxoinc: pertaining to a state or condition where in the axis of the foot lies between the third and forth digits.
The two major orders of ungulates • Perissodactyla : • contains only seventeen living species • horses • the rhinoceroses • and the tapirs
What is the role of hooves? • The hoof is a vital to ungulate’s existence. • Enables them to adapt their environment • Absorb shock • provide traction • resist wear and fracturing • protect the sensitive structure within the hoof wall • support body weight • conduct moisture throughout the hoof wall. • Adjusting the rate and density of growth
Ungulates obtain the speed needed to survive, an evolutionary imperative which would not have been possible with out the development of the hoofs • Raising the heel and digits off of the ground increases the number of joints which move the legs forward. • It increases the rat of stride
How hooves are developed/evolved/? • Lifestyle : the development of hooves illustrates a major innovation in the evolution of running lifestyle, pushed on early ungulates by fast running predators.
Idea in future research • If the common ancestor of the two groups of hoofed mammals alive today was also the ancestor of several groups which don't have hooves at all, what make them related, what cause their difference?