Designed by Paul Smith 2006. This website is copyrighted by law.
Material contained herewith may not be used without the prior written permission of FAUNA Paraguay.
Photographs on this web-site were taken by Paul Smith, Hemme Batjes, Regis Nossent,
Alberto Esquivel, Arne Lesterhuis, José Luis Cartes, Rebecca Zarza and Hugo del Castillo and are used with their permission.
BRADYPODIDAE - THREE-TOED SLOTHS
General characteristics: A single species considered hypothetical in Paraguay on the basis of unconfirmed reports from the northern Chaco area. Rounded head, flattened snout, inconspicuous ears and forward-facing eyes. Facial vibrissae are sparse and the rostrum is covered with short hair, bordered with longer hair on the sides of the face and neck. The dense pelage is double-layered - the outer layer longer and thick, and the under layer short and fine - an arrangement that encourages the growth of algal symbionts that appear to assist in camouflage. Sloths are cryptic and slow-moving, easily overlooked where they occur. Sloths are highly adapted for a hanging arboreal existence, the front limbs being 1.5x larger than the rear limbs and the three digits on each foot unified and armed with long, curved claws. Each foot also possesses a long, calloused palmar and plantar pad. Tail is short, rounded, mobile and tapers distally with a fixed outward curve. Fossil record is lacking.
Cranial characteristics: Broad interorbital region lacking postorbital processes. Incomplete zygomatic arch with long dorsal and ventral processes. Rostrum reduced and prenasal is lacking. Foramina in the anterior nasopharynx, typical of most species in this family are absent in the Paraguayan species. Pterygoids elongated and uninflated.
Dental characteristics: They are equipped with simple cylindrical teeth that lack enamel and grow throughout life. Anterior chisel-shaped teeth 1/1 and molariform teeth 4/3 are also present.
Skeletal characteristics: The neck is equipped with 8 or 9 cervical vertebrae (instead of the usual mammalian 7) giving increased flexibility. Ball and socket joint between astralagus and fibula. Coracoid and acromial processes of the scapula united. Xenarthrous thoracic and lumbar vertebrae.
DOWNLOAD A PDF OF THE COMPLETE HANDBOOK OF THE MAMMALS OF PARAGUAY VOLUME 2: XENARTHRA BY CLICKING HERE!! (14.3MB)
Bradypus Linnaeus, 1758: Three-toed Sloths
There are three species in this genus, one of which occurs in Paraguay. Synonyms adapted from Gardner (2007)
Bradypus Linnaeus 1758:34. Type species Bradypus tridactylus Linnaeus (1758).
Ignavus Blumenbach 1779:70. Type species Ignavus tridactylus Blumenbach (1779) (=Bradypus tridactylus Linnaeus 1758) by monotypy.
Pradypus Ledru 1810:257. Incorrect spelling.
Choloepus Desmarest 1816:327. In part. Not Chloepus Illiger (1811).
Acheus F.Cuvier 1825:194. Type species Bradypus tridactylus Linnaeus (1758) by monotypy.
Achaeus Erman 1835:22. Incorrect spelling. Not Achaeus Leach (1817) crustacea.
Achaeus Gray 1843:xxviii. Incorrect spelling. Not Achaeus Leach (1817) crustacea.
Arctopithecus Gray 1843:xxviii. Nomen nudum.
Arctopithecus Gray 1850:65. No type species selected. Preoccupied by Arcopithecus Virey (1819) primates.
Scaeopus W.Peters 1864:678. Type species Bradypus torquatus Illiger (1811) by monotypy.
Hemibradypus R.Anthony 1906:292. No type species selected. Type species Hemibradypus mareyi R.Anthony (1907) by designation
Eubradypus Lönnberg 1942:5. Type species Bradypus tridactylus Linnaeus (1758). Proposed as a subgenus of Bradypus Linnaeus (1758).
Neobradypus Lönnberg 1942:10. No type species selected. Name unavailable. Proposed as a subgenus of Bradypus Linnaeus (1758).
General characteristics: This is the only genus in this family and characteristics are given in the family account above.
There are unconfirmed anecdotal reports of sloths in the Paraguayan Chaco which have been tentatively attributed to the widespread Bradypus variegatus, Brown-throated Three-toed Sloth. Redford & Eisenberg (1992) mapped the species for the Cerro León area (Departamento Boquerón), presumably on the basis of such reports, but Gardner (2007) notes that the species “has not been recorded from Paraguay”, although he mentions a published report by Bertoni (1939) which lacked further data. His mapping of the species in the extreme east of the Paraguayan Orient (approximately Departamentos Amambay, Canindeyú and Alto Paraná) is the result of joining the range extremes of known specimens and shading the intervening area, it is not based on physical evidence of the species presence. In fact no sloths were found following the flooding caused by the Itaipú Dam, and data from rescue missions after flooding elsewhere in South America have tended to find sloths more abundant than had previously been realised. The species would therefore seem to be absent from the Atlantic Forest of Paraguay. The CDC lists the species for Paraguay but no specimens have apparently been collected and it is uncertain what the basis of the listing is (Hugo del Castillo pers. comm.). A report of an individual crossing a road near Madrejón, PN Defensores del Chaco, Departamento Boquerón by Inginiero Dany Levi requires investigation, though I have been unable to trace him.
Bradypus variegatus - Brown-throated Three-toed Sloth HYPOTHETICAL
Edentate Specialist Group - Publishes the online journal Edentata dealing with armadillos, sloths and anteaters.
Diaz MM & Barquez RM 2002 - Los Mamíferos de Jujuy, Argentina - LOLA.
Emmons LH & Feer F 1999 - Mamíferos de los Bosques Húmedos de América Tropical - FAN Bolivia.
Gardner AL 2007 - Mammals of South America Volume 1: Marsupials, Xenarthrans, Shrews and Bats - University of Chicago Press.
Redford K 1992 - Mammals of the Neotropics Vol 2: The Southern Cone Chile, Argentina, Uruguay and Paraguay - University of Chicago Press.