Vertebrae all short, much wider than long with articular surfaces flat. Ribs single-headed throughout. Coracoids without clavicular processes; posterior processes widely separated. Obturator foramina not separated? Ischia triradiate curved plates uniting at anterior-interior angle, posterior angles widely separated. Humerus and femur of equal length

Greek, leuros, 'smooth, even, flat', Greek, spondylus, 'vertebra': Flat vertebra.