Resumen de Morphology of hair of two-and three-toed sloths (Edentata: Bradypodidae)

Daniel E. Wujek, Joan M. Cocuzza

• español

  Los pelos del perezoso de dos dedos, Choloepus hoffmanni, tienen estrías longitudinales y una corteza uniforme (vista en corte transversal). Los pelos del perezoso de tres dedos, Bradypus variegatus, tienen fisuras transversales irregulares y una corteza con "fusi" diseminados. Las diferencias macromorfológicas apoyan la separación de ambos géneros en familias diferentes.

• English

  Micromorphological differences between hairs of the two-toed sloth (Choloepus hoffmanni) and of the three-toed sloth (Bradypus variegatus) were observed by means of scanning electron microscopy. Hairs of the two-toed sloth had longitudinal grooves which exposed a uniform cortex when viewed in cross section. Hairs of the three-toed sloth have irregular transverse fissures and a cortex that contains scattered fusi. These morphological differences support the placement of the two sloth genera into separate familes. Hairs of four other xenarthran species are al so illustrated.