Definition of "hystricognath"
hystricognath
noun
plural hystricognaths
(zoology) Any member of the infraorder Hystricognathi of rodents, distinguished from other rodents by the bone structure of their skulls.
Quotations
The New World hystricognath rodents (= caviomorphs) today represent one of the most diverse and widespread suborders among the over 800 mammal species of South America (Woods, 1982).
1996, José Roberto Moreira, David W. Macdonald, “7: Capybara use and conservation in South America”, in V.J. Taylor, N. Dunstone, editors, Exploitation of Mammal Populations, page 89
The situation is similar with respect to rodents, given that the earliest undisputed hystricognaths are from the Oligocene of Pakistan and Egypt (ca. 35Ma), with the possibility of a Middle Eocene origin for the group (Bryant and McKenna 1995; Marivaux et al. 2002).
2008, Felipe Bandoni de Oliveira, Eder Cassola Molina, Paul A. Garber, Gabriel Marroig, “Chapter 3: Paleogeography of the South Atlantic: a Route for Primates and Rodents into the New World?”, in Alejandro Estrada, Julio Cesar Bicca-Marques, Eckhard W. Heymann, Karen B. Strier, editors, South American Primates, page 63
The hystricognaths include several lines that radiated in Africa and South America in the Oligocene and Miocene. […] The largest hystricognath group is the Caviomorpha, the South American guinea pigs, capybaras, chinchillas and New World porcupines.
2009, Michael J. Benton, Vertebrate Palaeontology, page 359