MacFadden BJ, Solounias N, Cerling TE
Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA. Department of Anatomy, New York College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA. Department of Geology.
Science. 1999 Feb 5;283(5403):824-7. doi: 10.1126/science.283.5403.824.
Six sympatric species of 5-million-year-old (late Hemphillian) horses from Florida existed during a time of major global change and extinction in terrestrial ecosystems. Traditionally, these horses were interpreted to have fed on abrasive grasses because of their high-crowned teeth. However, carbon isotopic and tooth microwear data indicate that these horses were not all C4 grazers but also included mixed feeders and C3 browsers. The late Hemphillian Florida sister species of the modern genus Equus was principally a browser, unlike the grazing diet of modern equids. Late Hemphillian horse extinctions in Florida involved two grazing and one browsing species.
来自佛罗里达州的六种距今500万年（晚亨菲利期）的同域马种，生存于陆地生态系统发生重大全球变化和物种灭绝的时期。传统上，由于这些马的高冠齿，它们被认为以粗糙的草为食。然而，碳同位素和牙齿微磨损数据表明，这些马并非都是C4食草动物，还包括混合食性动物和C3食叶动物。现代马属的晚亨菲利期佛罗里达姐妹种主要是食叶动物，这与现代马科动物的食草习性不同。佛罗里达州晚亨菲利期马的灭绝涉及两个食草物种和一个食叶物种。
