PREHISTORIC CATS AND PREHISTORIC CAT-LIKE CREATURES

sabre-toothed cats,

….only a handful of prehistoric big cats exceeded an average weights of 100 kilos and only four or five North American prehistoric big cats (not all are true cats) are in the 100+ kilos category.

This means few were longer or taller at the shoulder than a modern leopard or jaguar.

Many of the "bigger" prehistoric big cats were compact, muscular animals. Modern big cats are relatively long-legged and lithe in comparison.Although they are often called "big cats" many of the prehistoric species were not true cats, but were cat-like mammals.

CONVERGENT EVOLUTION

“Cat analogues “

South America and Australia were both island continents and lacked placental mammals.

The "lions" and "tigers" of those continents were lion-like marsupials, more closely related to kangaroos, wombats and their like.

They are known as "cat analogues" as they resembled cats and filled the same ecological niche as cats.

CAT-LIKE

Aline of prehistoric cats were the Paleofelids ("ancientcats") that developed in parallel with the true cats and from a common ancestor, but which have left no modern descendants.

Finally there are the prehistoric true cats, extinct relatives of modern cats.

Why would evolution create creatures very similar in form to cats?

It's an example of convergent evolution -there are a limited number of solutions to environmental conditions hence animals that aren’t closely related often independently evolve similar traits as they both adapt to similar environments and niches.

The cat-like form has evolved at least three times: marsupial lions/tigers, Paleofelids and Neofelids.

Sabre-toothed cat-like animals evolved separately four times in evolutionary history: Nimravids,

Felids,Creodontsand the Thylacosmilids.

The taxonomy (classification) of both living and extinct species changes frequently.

As more fossilevidence comes to light, species are reclassified. Some are given their own species or genus whileothers are absorbed into an existing species or genus and their original classification is scrapped

Lion skeleton

Vergelijkende anatomie

Spierbeeld  van  de  voorpoot van  de  leeuw  ( A ) en  de  arm  van  de  mens  ( B ) .TIJDSCHAAL

Although there are references to animals being found in places far apart on the modern world map, the continents used to look very different. Some land masses that were once joined together have nowsplit and drifted apart, others that were far apart have collided. Some land masses that are currently not joined to each other were joined by ancient land bridges when sea levels were much lower thanthey are today.

EVOLUTION OF MODERN CATS (SUMMARY)

Carnivorous mammals evolved from Miacids small pine marten-like insectivores that lived 60 million -55 million years ago.

The miacids split into two lines: Miacidae and Viverravidae.

Miacidae gave rise toArctoidea/Canoidea group (bears and dogs) while Viverravidae gave rise to Aeluroidea/Feloidea group(cats, hyenas, civets, mongooses) around 48 million years ago.

The Viverravidae also gave rise to agroup called Nimravidae.

The Nimravids were cat-like creatures that evolved in parallel with true cats;they are not part of true cat lineage and have left no living descendents.

The first true cat to arise from Viverravidae was Proailurus (first cat") around 30 million years ago.

The best-known species was P lemanensis, found in France.

Proailurus was a small weasel-like cat with relatively short legs and a long body. It had one more premolar on each side of its bottom jaw than do modern cats.

About 20 million years ago, Proailurus gave rise to Pseudaelurus. Pseudaelurus were Miocene ancestors of cats. Pseudaelurus lorteti wasabout the size of a large lynx while P validus was the size of a large lynx or small puma.

Three other species of early cat are described as Pratifelis, Vishnufelis and Sivaelurus (S chinjienis).Pseudaeluruswent on to split into two major groups:the Machairodontinae (true sabre-tooths) and Schizailurus (theancestor of the modern day Felidae group).

http://en.wikipedia.org/wiki/Proailurushttp://it.wikipedia.org/wiki/Proailurus_lemanensis

Smilodon populator

Dinocrocuta giganteum