New Scientific Paper Has Explained How Giraffes Grew Long Necks
The long iconic neck of giraffe is the one of the most discussed topics among scientists and several evolutionary theories are proposed to explain the evolution of this elongated giraffe neck.
Giraffes, like humans, have seven cervical vertebrae, but the giraffe’s vertebrae are large, measuring up to 10 inches (25.4 centimeters) long. Samotherium major is a member of the modern giraffe family. 7 million years ago this species stretched the front side of their neck that contributed to the neck elongation of other giraffe species.
The main discovery came after the researchers analysed anatomical features of the various fossils and compared them to the evolutionary tree.
Scientists have long theorized that the long neck of modern-day giraffes evolved to enable them to find more vegetation or to develop a specialised method of fighting. The researchers studied 71 fossils belonging to nine extinct species of early giraffes, and conducted a comparison to two common living species in the giraffe family, according to the Daily Mail.
The evolution of the giraffe neck was not consistent and took place in several stages, with each stage separated by millions of years.
Apparently, modern species of giraffes developed this new physical characteristic 16 million years ago.
Dr Nick Solounias, a giraffe anatomy expert and palaeontologist at NYIT, said: ‘It’s interesting to note that that the lengthening was not consistent. In one species of giraffe, only the front portion of the vertebrae had lengthened, while the second stage was the lengthening of the back portion of the neck vertebrae.
Not only giraffes, the sauropod dinosaurs and aquatic plesiosaurs also stretched out to long necks both by adding additional vertebrae to the column and elongating those individual bones. In fact, the modern species (Giraffa camelopardalis) is the only one that underwent both stages of growth: head and tail.
“The primitive giraffe already started off with a slightly elongated neck”, said Melinda Danowitz, co-author of the study.
For future study, researchers want to examine the evolution of giraffe’s long leg bones.
“The lengthening started before the giraffe family was even created 16 million years ago”, said Danowitz, who is a medical student in the school’s Academic Medicine Scholars program, as Eurekalert informed.
The long neck of the giraffe (left) allows them to browse leaves from branches high on trees in the African Savannah (right) but is also used by males in fights over females, where they swing their necks like giant clubs.