Trichechus inunguis (Natterer, 1883)

Voss, Robert S. & Fleck, David W., 2017, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 2: Xenarthra, Carnivora, Perissodactyla, Artiodactyla, And Sirenia, Bulletin of the American Museum of Natural History 2017 (417), pp. 1-1 : 1-

Trichechus inunguis (Natterer, 1883)

VOUCHER MATERIAL: Río Tapiche (AMNH 98691).

OTHER INTERFLUVIAL RECORDS: Jenaro Herrera (Tovar, 2011), Reserva Comunal Tamshiyacu-Tahuayo ( Bodmer, 1994), Río Orosa (Mármol, 1995), Río Tapiche (Reeves et al., 1996), Río Yavarí (Mármol, 1995).

IDENTIFICATION: Only a single species of manatee is known to occur in the upper Amazon Basin. Our voucher consists of the skull of a mature adult of unknown sex. Selected cranial measurements of AMNH 98691 are all within the range of variation for Trichechus inunguis tabulated by Domning and Hayek (1986): condylobasal length, 383.1 mm; breadth across postorbital processes of frontals, 130.1 mm; least postorbital breadth, 54.1 mm; zygomatic breadth, 214.1 mm.

REMARKS: The holotype skull of an allegedly new species of “dwarf ” manatee recently described by Roosmalen (2015: figs. 20, 21) from the Rio Aripuanã basin of Amazonas, Brazil, is an obviously immature individual with open basicranial and occipital sutures.