mom << What did giraffes evolve from? Can evolutionists show me some sign that their evolution occurred, other than the fact that they are here? Well, no, but the reason you’re supposed to believe it is that you are either ignorant or a religious zealot if you don’t >>
What you want to look up is general
Artiodactyl evolution (e.g. pigs, hippos, deer, giraffes, cows) :
Lophiomeryx, Gelocus (late Eocene, early Oligocene) – The most advanced ruminants yet, called “gelocids”, with a more compact and efficient ankle, still smaller side toes, more complex premolars and an almost completely covered mastoid bone. A slightly different lineage split off from this gelocid family in the late Eocene or early Oligocene, eventually giving rise to these four families:
Deer: Prodremotherium (late Eocene), a slightly deerlike ruminant, and Eumeryx (Oligocene), a more deer-like ruminant, Dicrocerus (early Miocene), with the first antlers (similar to living muntjacs), Acteocemas (Miocene), and then a shmoo of successful Miocene & Pliocene groups that survive today as modern deer – cervines, white- tails, moose, reindeer, etc.
Giraffes: Branched off from the deer just after Eumeryx. The first giraffids were Climacoceras (very earliest Miocene) and then Canthumeryx (also very early Miocene), then Paleomeryx (early Miocene), then Palaeotragus (early Miocene) a short-necked giraffid complete with short skin-covered horns. From here the giraffe lineage goes through Samotherium (late Miocene), another short-necked giraffe, and then split into Okapia (one species is still alive, the okapi, essentially a living Miocene short-necked giraffe), and Giraffa (Pliocene), the modern long-necked giraffe.
Pronghorns: Paracosoryx prodromus (early Miocene, 21 Ma) a primitive antilocaprid, probably derived from a North American branch of the bovid lineage. Next came Merycodus (Miocene), with branched permanent horns. Led to numerous antilocaprids in the Pliocene. Only the pronghorn is still alive.
Bovids: known from isolated teeth in the late Oligocene, then from Eotragus, a primitive ancestral mid-Miocene bovid. Protragocerus (Miocene) soon followed. The first sheep (Oioceros) and gazelles (Gazella) are known from the mid-late Miocene (14 Ma), the first cattle (Leptobos, Parabos) from the early Pliocene (5 Ma).
From the TalkOrigins
Transitional Vertebrate Fossils FAQ Part 2C with conclusion (read the conclusion also).
See Carroll,
Vertebrate Paleontology and Evolution (1988): “The early evolution of the artiodactyls is fairly well documented by both the dentition and considerable skeletal material and provides the basis for fairly detailed analysis of evolutionary patterns…the origin of nearly all the recognized families can be traced to the late Middle Eocene or the Upper Eocene…” (page 507).
A recent book by a professional geologist / paleontologist
Donald Prothero Evolution: What the Fossils Say and Why It Matters (Columbia Univ Press, 2007). The evolution of giraffes (with pictures) is discussed on pages 316-318: “…Nikos Solounias is currently publishing a description of a classic transitional form (figure mentioned): a giraffe fossil with an intermediate-length neck, longer than that of the
okapi and the other extinct forms but shorter than that of the living giraffes. For so many years, people have speculated about how giraffes got their long necks, and now we finally have the fossils to show exactly how it happened! Once again, the fossil record has yielded a transitional form that the creationists claimed could never exist.” (Prothero, page 316)
Diagrams on page 317 describes the latest evidence for the giraffe family evolution: (A) the modern
okapi is more typical of the group, with its short neck and relatively short horns or “ossicones.” Some fossil giraffids, however, had very unusual branching and flaring cranial appendages. Only the lineage of the modern giraffid evolved a long neck. (B) The modern
okapi, much more typical of the giraffe family than its long-necked cousin. The oldest ancestors of the giraffe (Paleoryx, Canthumeryx) date from 23 million years ago. Samotherium branched off about 20 million years ago which led to “Paleotragus” which branched off to Bohlinia which led to Giraffa (the modern long-necked). About 12 extinct species (various necks and appendages) are listed.
Fossil Record of the Artiodactyla
Artiodactyl Evolution from Britannica
Artiodactyla References
I AM a religious zealot, AND I accept the evidence for the evolution of whales and giraffes. Religious zealots like me know how to read science books and keep themselves from being ignorant at the same time. Kind of like rubbing your tummy and patting your head together.
Phil P