Browsing by Author "Woods, Charles A. (Charles Arthur)"
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Item Comparative myology of jaw, hyoid, and pectoral appendicular regions of New and Old World hystricomorph rodents. Bulletin of the AMNH ; v. 147, article 3(New York : [American Museum of Natural History], 1972) Woods, Charles A. (Charles Arthur)"The musculature of 13 genera of New World and Old World hystricomorphous rodents was studied by dissection. The genera investigated were Proechimys, Echimys, Isothrix, Mesomys, Myocastor, Octodon, Ctenomys, Erethizon, Cavia, Chinchilla, and Dasyprocta of the New World, and Thryonomys and Petromus of the Old World. The objective of the investigation was to explore the myological characteristics of these rodents as an aid in better understanding their evolutionary history. The hystricognathous mandible that is found in most hystricomorphous rodents is associated with pars reflexa of the superficial masseter muscle. The elongated angular process is associated with the internal pterygoid muscle and with the superficial masseter. The posterior deep part of the lateral masseter muscle lies horizontally, and is associated with the post-condyloid process of these rodents. The temporal muscle is composed mainly of the posterior division. All of these specializations are probably related to the anterior-posterior movement of the jaw. The stylohyoid muscle is missing in all genera investigated (and in bathyergids). The scalenus anterior is present in all genera except Erethizon. The scapuloclavicularis muscle is found in all genera, and is similar in Thryonomys and Dasyprocta. The cutaneus maximus is similar in all genera and unlike the muscle in any other group of rodents. The evidence indicates that New World and Old World hystricomorphs probably represent a common group. This group might have evolved from a hystricognathous paramyid subgroup in the mid-Eocene. Another view is that the group might be a consequence of an invasion of South America by African froms via rafting across the then narrower Atlantic Ocean"--P. 119.Item New megalonychid sloths (Phyllophaga, Xenarthra) from the Quaternary of Hispaniola. American Museum novitates ; no.3303(New York, NY : American Museum of Natural History, 2000) MacPhee, R. D. E.; White, Jennifer L. (Jennifer Lynn); Woods, Charles A. (Charles Arthur)As part of ongoing revisionary work on Antillean Megalonychidae, we document four new sloth species from Quaternary cave localities in Haiti and the Dominican Republic. The new taxa and their tribal affiliations are as follows: Megalocnus zile (Megalocnini), Acratocnus ye (Acratocnini), and Neocnus dousman and N. toupiti (Cubanocnini). Significantly, each is closely related to species in genera long known from Cuba. This observation is of primary biogeographical importance because the most parsimonious explanation for the presence of parallel arrays of lower-level clades of sloths on opposite sides of the Windward Passage is vicariance, not a series of uncoordinated over-water dispersals. For a brief period in the late Paleogene, eastern Cuba, northern Hispaniola, Puerto Rico, and the Aves Rise formed a large positive structure (GAARlandia) that was evidently briefly continuous with northwestern South America. We infer that the later subdivision and subsidence of major portions of GAARlandia must have finely vicariated its biota (which included sloths at least as early as the early Oligocene). On this argument, Megalocnus, Acratocnus, Neocnus, and Parocnus (= Mesocnus) must have already been in existence as independent clades at the time of origin of the Windward Passage (early Neogene), because cladistically diagnosable members of these taxa occur in Quaternary contexts in both Cuba and Hispaniola. This interpretation is consistent with several new lines of evidence concerning the paleontological and paleogeographical history of the Caribbean region.