Researchers Find Evidence in 7-Million-Yr-Old Fossil of How Giraffes Evolved To Have Such Admirably Long Necks
Giraffes are majestic animals, whose long necks make them stand apart from other beings. For a long time, researchers have been trying to figure out how giraffes acquired this feature, stated ABC. In 2015, certain examinations showcased to a team of experts how the physical attributes got incorporated into giraffes. Findings regarding those examinations were published in Royal Society Open Science.
For a long time, experts thought that evolution was why giraffes exhibited the long neck. However, researchers did not have fossil evidence to back up this claim. The team associated with the study examined the remains of Samotherium major excavated from Samos in Greece. Researchers believe that the discovered remains belonged to around four individuals. "The bones might not be one individual, but considering the rarity of well-preserved fossil necks, it is likely they came from very few individuals, and that several of the bones came from the same individual," Senior author, Professor Nikos Solounais said.
The team associated with the study had already conducted examinations that proved S.major to be the first species to experience neck elongation in the giraffe family. The first stage of the neck elongation process which involves expansion of the cranial end of each neck bone was observed in this species. However, the next step in which the caudal end of each bone expands was not noted in this species. The species went extinct around seven million years ago. The giraffid frequented places like China, Moldavia, Turkey, Iran, Greece, and Italy. Researchers compared the discovered vertebrae with the neck bones of living species from the Giraffidae family - the giraffe (Giraffa camelopardalis) and okapi (Okapia johnstoni), to verify if evolution was the reason behind the group's neck elongation.
The experts observed that the neck of all three comprised seven bones. The team noted differences in the length of the necks. The present-day giraffe's neck on average was two metres long. In the case of the discovered fossil, the neck was estimated to be around one meter. Okapi's neck was much shorter at 60 centimeters. The measurement aligned with past assertions that claimed S.Major to be a "transitional" or "intermediate" species between okapi and modern giraffes. This further backs the theory that long necks were an evolutionary characteristic adopted by G.camelopardalis. "We can finally see the transitional stages in the elongation of the giraffe neck," Co-author Ms Melinda Danowitz said.
Researchers noted that along with the long neck, several other intermediate characteristics used to be exhibited by S.major. In okapi's sixth neck bone a ventral ridge was recorded. This ridge was absent in the giraffe, but in S.major the ridge was located in half of the bone. "In the okapi, the ventral lamina is a large, complete square-shaped plate, and in the giraffe, it is completely excavated, making a crescent," Ms Danowitz said. "In Samotherium, it has a shape intermediate between the two, where the ventral lamina is present but has a large notch." According to researchers the available evidence implies that even if S.major was not a direct predecessor, it was likely a close relative.