Giraffe Neck Evolution Traced to Two Key Stages of Lengthening in a Single Vertebra (C3); the Two Lengthenings Took Place 6 Million Years Apart and in Different Directions

Scientists have long theorized that the long neck of modern-day giraffes evolved to enable them to find more vegetation or to develop a specialized method of fighting. A new study of fossil cervical vertebrae reveals the evolution likely occurred in several stages as one of the animal's neck vertebrae stretched first toward the head and then toward the tail a few million years later. The study's authors say the research shows, for the first time, the specifics of the evolutionary transformation in extinct species within the giraffe family. "It's interesting to note that that the lengthening was not consistent," said Dr. Nikos Solounias, a giraffe anatomy expert and paleontologist at the New York Institute of Technology (NYIT) College of Osteopathic Medicine. "First, only the front portion of the C3 vertebra lengthened in one group of species. The second stage was the elongation of the back portion of the C3 neck vertebra. The modern giraffe is the only species that underwent both stages, which is why it has a remarkably long neck."The study, which includes a computational tracking model of the evolutionary elongation, was published online on October 7, 2015 in an open-access article in the journal Royal Society Open Science. The article is titled "Fossil Evidence and Stages of Elongation of the Giraffa camelopardalis Neck." Dr. Solounias and Melinda Danowitz, a medical student in the school's Academic Medicine Scholars program, studied 71 fossils of nine extinct and two living species in the giraffe family. The bones, discovered in the late 1800s and early 1900s, were housed at museums around the world, including ones in England, Austria, Germany, Sweden, Kenya, and Greece. "We also found that the most primitive giraffe already started off with a slightly elongated neck," said Danowitz.
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