Pollen evidence for Late Cretaceous differentiation of Proteaceae in southern polar forests

Sclerophyllous Adenanthos and Stirlingia (Proteoideae) are now restricted to the S Australian Mediterranean climatic region: Persoonia (Persoonioideae) ranges into higher rainfall areas of E and N Australia. Grevillea exul-Grevillea robusta and Telopea (Grevilleoideae) and Carnarvonia (Carnarvonioideae) occur in or at the fringe of rain forests in E Australasia, as do other members (Macadamia, Gevuina-Hicksbeachia, Knightia, Beauprea) reported previously. Pollen evidence confirms evolution of both rain forest and sclerophyll members of the Campanian-Maastrichtian. Turnover of proteaceous pollen taxa near the Cretaceous-Tertiary boundary may reflect contemporaneous modifications to the proteaceous communities. Associated with the Late Cretaceous Proteaceae were diverse conifers (Microcachrys, Lagarostrobus, Podocarpus, Dacrydium, Dacrycarpus and Araucariaceae), Nothofagus, Ilex, Gunnera, Ascarina, Winteraceae, Trimeniaceae, and probable Epacridaceae. The vegetation, which fringed a narrow estuary separating Antarctica from southern Australia, implies a mosaic of rain forest and sclerophyll communities but has no modern analogue. -from Author

Tracking the Mesozoic distribution of Gunnera: comparison with the fossil pollen species Tricolpites reticulatus Cookson

The morphology of the exine of Late Cretaceous and Tertiary specimens of Tricolpites reticulatus previously documented from Kerguelen, the Antarctic Peninsula, and the Otway Basin of southeastern Australia has been re-examined and compared with the three pollen types identified in the genus Gunnera. An Antarctic specimen of T reticulatus (Maastrichtian) has a uniform reticulum with elongated lumina, similar to that characterising pollen type 3a of Gunnera macrophylla (subgenus Pseudogunnera). Late Cretaceous (Maastrichtian) Australian specimens of T reticulatus differ; specimens from McNamara resemble pollen of subgenera Pseudogunnera and Milligania of type 3a or type 3b, while specimens of T reticulatus from Princes show more rounded and equidimensional lumina and are therefore tentatively attributed to pollen type 2 found in subgenera Gunnera, Misandra and Panke. Kerguelen Island T reticulatus (Miocene) are distinct from Vega Island specimens: a closer resemblance of Kerguelen T reticulatus and pollen type 2 of extant Gunnera is hypothesised. A comparison between specimens of the North American Tricolpites reticulatus/microreticulatus and pollen of Gunnera is also made. The clear similarity of the North American specimens of Tricolpites microreticulatus and pollen of Gunnera in shape and in the exine surface features of pollen suggests that this taxon should not be separated from T reticulatus but should be treated as a synonym of this species. (C) 2004 Elsevier B.V. All rights reserved

Exceptionally well preserved late Quaternary plant and vertebrate fossils from a blue hole on Abaco, The Bahamas

We report Quaternary vertebrate and plant fossils from Sawmill Sink, a “blue hole” (a water-filled sinkhole) on Great Abaco Island, The Bahamas. The fossils are well preserved because of deposition in anoxic salt water. Vertebrate fossils from peat on the talus cone are radiocarbon-dated from ≈4,200 to 1,000 cal BP (Late Holocene). The peat produced skeletons of two extinct species (tortoise Chelonoidis undescribed sp. and Caracara Caracara creightoni) and two extant species no longer in The Bahamas (Cuban crocodile, Crocodylus rhombifer; and Cooper's or Gundlach's Hawk, Accipiter cooperii or Accipiter gundlachii). A different, inorganic bone deposit on a limestone ledge in Sawmill Sink is a Late Pleistocene owl roost that features lizards (one species), snakes (three species), birds (25 species), and bats (four species). The owl roost fauna includes Rallus undescribed sp. (extinct; the first Bahamian flightless rail) and four other locally extinct species of birds (Cooper's/Gundlach's Hawk, A. cooperii/gundlachii; flicker Colaptes sp.; Cave Swallow, Petrochelidon fulva; and Eastern Meadowlark, Sturnella magna) and mammals (Bahamian hutia, Geocapromys ingrahami; and a bat, Myotis sp.). The exquisitely preserved fossils from Sawmill Sink suggest a grassy pineland as the dominant plant community on Abaco in the Late Pleistocene, with a heavier component of coppice (tropical dry evergreen forest) in the Late Holocene. Important in its own right, this information also will help biologists and government planners to develop conservation programs in The Bahamas that consider long-term ecological and cultural processes