Browsing by Author "Morgan, Gary S."
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Item Contributions to mammalogy in honor of Karl F. Koopman. Bulletin of the AMNH ; no. 206([New York] : American Museum of Natural History, 1991) Griffiths, Thomas Alan.; Klingener, David.; Handley, Charles O.; Owen, Robert D.; Peterson, R. L.; Baker, Robert J.; Honeycutt, Rodney L.; Van Den Bussche, Ronald A.; Freeman, Patricia Waring.; Lemen, Cliff A.; Smith, Andrea L.; Novacek, Michael J.; Pacheco Torres, Victor R. (Victor Raul); Patterson, Bruce D.; Ryan, James M.; Anderson, Sydney.; Heaney, Lawrence R.; Hill, John E.; Morgan, Gary S.; Wilson, Don E.; Timm, Robert M.; Lewis, Susan E.; Lawrence, Marie A.; MacPhee, R. D. E.; Fleagle, John G.; Musser, Guy G.; Holden, Mary Ellen.; Voss, Robert S.; Myers, Philip.Item The Cuban crocodile (Crocodylus rhombifer) from late Quaternary underwater cave deposits in the Dominican Republic. (American Museum novitates, no. 3916)(American Museum of Natural History., 2018-12-21) Morgan, Gary S.; Albury, Nancy Ann, 1955-; Rímoli, Renato O.; Lehman, Phillip.; Rosenberger, Alfred L.; Cooke, Siobhán B.Late Quaternary fossils representing a locally extinct population of the Cuban crocodile (Crocodylus rhombifer) are reported from two underwater caves in the Dominican Republic. A large fossil sample of C. rhombifer, from Oleg's Bat Cave near Bavaro in the southeastern Dominican Republic, consists of four nearly complete skulls, numerous isolated cranial elements and mandibles, and more than 100 postcranial bones representing most of the skeleton. These fossils were collected from a completely submerged portion of the cave at a depth of 11 m and about 100 m from the nearest entrance. A skull, mandibles, and two vertebrae of a Cuban crocodile were also found in a second cave called Ni-Rahu, northeast of Santo Domingo. We identify the fossil crocodile skulls from the Dominican Republic as Crocodylus rhombifer because they share the following characters with modern skulls of C. rhombifer from Cuba (as well as fossil skulls from Cuba, the Bahamas, and Cayman Islands): short, broad, and deep rostrum; large orbits; convex nasals along the midline (midrostral boss); prominent swelling on the lacrimals anterior and medial to the orbits; low but obvious ridges extending anteriorly from the lacrimals to the nasals and posteriorly from the lacrimals to the prefrontals and frontals, outlining a distinct diamond- or rhomboid-shaped structure; strongly concave interorbital region and cranial roof; high, narrow ridges on the internal margins of the orbits, extending from the prefrontals to the frontals and posteriorly to the postorbitals; prominent ridges along the lateral margins of the cranial roof on the postorbitals and squamosals, terminating as noticeable protuberances on the posterolateral corners of the squamosals; premaxillary/maxillary suture on the palate essentially horizontal or transverse to the long axis of the skull at the level of the first maxillary tooth; 13 teeth in the maxilla. Certain aspects of the ecology and anatomy of living Crocodylus rhombifer in Cuba, and carbon isotope data from fossil crocodile bones from both the Dominican Republic and the Bahamas, indicate that the Cuban crocodile is a terrestrially adapted predator. The fossil deposits in Oleg's Bat Cave and other underwater caves in the Dominican Republic lack freshwater vertebrates, such as fish and turtles, but contain abundant samples of hystricognath rodents, small ground sloths, and other terrestrial vertebrates, including large land tortoises, that apparently were the primary prey of the crocodiles. Bats are abundant in the fossil deposits in Oleg's Bat Cave, and may have been an additional food source. Bone collagen from a tibia of C. rhombifer from Oleg's Bat Cave yielded an AMS radiocarbon date of 6460 ±30 ryrBP (equivalent to 7320 to 7430 cal yrBP). The chronology for the local extinction of C. rhombifer in Hispaniola is currently unknown, except to document the presence of this species in the eastern Dominican Republic in the early Holocene. Radiocarbon dates and historical records confirm that Cuban crocodiles survived into the period of European colonization (post-1492) in the Bahamas and on Grand Cayman. The only species of crocodile currently found in Hispaniola, the American crocodile (C. acutus), occurs in coastal marine habitats and in two inland brackish-water lakes: Lago Enriquillo in the Dominican Republic and the nearby Etang Saumâtre in Haiti. C. acutus has no fossil record in Hispaniola or elsewhere in the West Indies, suggesting that this species may be a very recent (late Holocene) immigrant in the Antillean region. Crocodylus rhombifer has one of the most limited geographic ranges of any living crocodylian species, known only from freshwater swamps in south-central Cuba and the Isla de Juventud (Isla de Pinos) off the southwestern coast of Cuba. Locally extinct or extirpated populations of C. rhombifer from fossil deposits in the Dominican Republic, Grand Cayman, and the Bahamas document a considerably wider distribution for this species during the Late Quaternary.Item Late Quaternary fossil mammals from the Cayman Islands, West Indies. (Bulletin of the American Museum of Natural History, no. 428)(American Museum of Natural History., 2019-03-04) Morgan, Gary S.; MacPhee, R. D. E.; Woods, Roseina.; Turvey, Sam.Abundant fossils of nesophontid lipotyphlan insectivores and capromyid rodents have been collected from late Quaternary deposits on the Cayman Islands, an island group separated by a major marine barrier from other Caribbean landmasses and isolated from anthropogenic impacts until the arrival of Columbus in 1503 CE. These collections have not previously been formally described. Using morphological and ancient DNA approaches, we document three new taxa of extinct endemic terrestrial mammals from this island group: Nesophontes hemicingulus (Grand Cayman and Cayman Brac), Capromys pilorides lewisi (Grand Cayman, Little Cayman, and Cayman Brac), and Geocapromys caymanensis (Grand Cayman and Cayman Brac). Morphometric comparisons with other extinct and living West Indian mammals indicate that the biogeographic origins of all three new taxa are from source populations on Cuba. Ancient DNA data indicate very low sequence divergence of Capromys pilorides lewisi from mainland Cuban C. pilorides (only 0.5% across the entire mitogenome). Using probabilistic analysis of existing and new radiometric dates, we calculate an estimated extinction date of 1700 CE (95% confidence interval = 1632-1774 CE) for the Cayman Brac Capromys population. This result suggests that at least one endemic Cayman terrestrial mammal population survived for well over a century following first European arrival in the Cayman Islands. The West Indies lost nearly all its species-rich late Quaternary land mammal fauna during the late Holocene due to direct or indirect human impacts, and this study provides a new baseline to understand the magnitude of human-caused mammal extinctions during the recent past.Item A new mormoopid bat from the Oligocene (Whitneyan and early Arikareean) of Florida, and phylogenetic relationships of the major clades of Mormoopidae (Mammalia, Chiroptera). (Bulletin of the American Museum of Natural History, no. 434)(American Museum of Natural History., 2019-06-17) Morgan, Gary S.; Czaplewski, Nicholas J.; Simmons, Nancy B.A new genus and species of fossil bat, Koopmanycteris palaeomormoops, representing an ancient member of the endemic Neotropical family Mormoopidae, is described from the Oligocene of Florida. This new species is known from two paleokarst deposits in northern peninsular Florida, the early Oligocene (Whitneyan, 30-32 Ma) I-75 Local Fauna in Alachua County and the late Oligocene (early Arikareean, 26-28 Ma) Brooksville 2 Local Fauna in Hernando County. The discovery of Koopmanycteris extends the fossil record of the Mormoopidae back in time almost 30 million years. Compared to most other described taxa of North American Tertiary bats, the fossil sample of Koopmanycteris palaeomormoops is substantial, consisting of 50 specimens including: P4, all lower teeth from p3 through m3, dentary, petrosal, humerus, proximal radius, and femur. Koopmanycteris is morphologically intermediate between the two living genera of mormoopids, Mormoops and Pteronotus, but is most similar to the former taxon. Characters shared by Koopmanycteris and Mormoops include: large anterolabial basin on P4; large, double-rooted p3; secondary process ventral to angular process on dentary; absence of groove separating capitulum into medial and lateral portions on distal humerus; presence of prominent ridge on posterolateral edge of distal humeral shaft; rounded extremity on proximal radius; and presence of a prominent ridge or tubercle on posterodistal shaft of femur. All of these features appear to be relatively derived, with the exception of the large, double-rooted p3. In several mandibular characters, Koopmanycteris more closely resembles Pteronotus, including: pronounced posteroventral process on the symphysis; lack of curvature of ventral edge of horizontal ramus between posterior edge of symphysis and p4; and less pronounced dorsal upturning of ascending ramus compared to Mormoops. Koopmanycteris retains the primitive dental morphology of Mormoops, with a large double-rooted p3, and the primitive posterior mandibular morphology of Pteronotus, with the lesser degree of dorsal flexion of the ascending ramus. A phylogenetic analysis including all known extant mormoopid lineages as well as representative outgroups from other noctilionoid clades confirms that Koopmanycteris and Mormoops are sister taxa. These findings indicate that the lineages leading to Pteronotus and Mormoops were distinct by ~30 Ma. The fossil record tentatively indicates that the Mormoopidae originated in North America in the early Oligocene or earlier, and may not have reached South America until the Pliocene following the onset of the Great American Biotic Interchange. Several lines of evidence support this hypothesis: (1) the earliest fossil record of the Mormoopidae is in the early Oligocene of Florida; (2) the greatest diversity and endemism of modern mormoopid species is in the West Indies; and (3) the absence of a pre-late Pleistocene record, lack of endemism, and marginal recent distribution of mormoopids in South America. Most species of living mormoopids are obligate cave dwellers, suggesting that the occurrence of caves and paleokarst deposits has affected both their modern distribution and fossil record.Item Vertebrate fossils and their context : contributions in honor of Richard H. Tedford. Bulletin of the AMNH ; no. 279(New York, NY : American Museum of Natural History, 2003) Flynn, Lawrence J. (Lawrence John), 1932-; Tedford, Richard H.; Novacek, Michael J.; Woodburne, Michael O.; Hunt, Robert M., Jr., 1941-; Gould, Gina C.; Gaffney, Eugene S.; Qiu, Zhanxiang.; Demere, Thomas A.; Berta, Annalisa.; Adam, Peter J.; Wang, Banyue.; Baskin, Jon A.; Van Valkenburgh, Blaire.; Sacco, Tyson.; Wang, Xiaoming, 1957-; Stevens, Margaret Skeels.; Stevens, James Bowie.; Lindsay, Everett H.; Whistler, David P.; Lander, E. Bruce.; Morgan, Gary S.; Lucas, Spencer G.; Ferrusquia-Villafranca, Ismael.; Webb, S. David (Sawney David), 1936-; Beatty, Brian Lee.; Poinar, George.; MacFadden, Bruce J.; Repenning, Charles A.; Turnbull, William D.; Lundelius, Ernest L.; Archer, Michael, 1945-; Pledge, Neville S.; Rich, Thomas H. V.; Darragh, Thomas A.; Rich, Pat Vickers.; Ye, Jie.; Meng, Jin (Paleontologist); Wu, Wenyu.; Qiu, Zhuding.; Li, Chuan-Kuei.; Winkler, Alisa J.; Downs, Will.; Holec, Peter.; Emry, Robert J.; McKenna, Malcolm C.; Lofgren, Donald L.; Tong, Haiyan.