David M. Jarzen

Early steps of angiosperm–pollinator coevolution

The hypothesis that early flowering plants were insect-pollinated could be tested by an examination of the pollination biology of basal angiosperms and the pollination modes of fossil angiosperms. We provide data to show that early fossil angiosperms were insect-pollinated. Eighty-six percent of 29 extant basal angiosperm families have species that are zoophilous (of which 34% are specialized) and 17% of the families have species that are wind-pollinated, whereas basal eudicot families and basal monocot families more commonly have wind and specialized pollination modes (up to 78%). Character reconstruction based on recent molecular trees of angiosperms suggests that the most parsimonious result is that zoophily is the ancestral state. Combining pollen ornamentation, size, and aperture characteristics and the abundance of single-species pollen clumps of Cenomanian angiosperm-dispersed pollen species from the Dakota Formation demonstrates a dominance of zoophilous pollination (76% versus 24% wind pollination). The zoophilous pollen species have adaptations for pollination by generalist insects (39%), specialized pollen-collecting insects (27%), and other specialized pollinators (10%). These data quantify the presences of more specialized pollination modes during the mid-Cretaceous angiosperm diversification.

Fungal palynomorphs recovered from Recent river deposits, Luangwa Valley, Zambia

Abstract Fifty‐five forms of fungal palynomorphs including spores, fragments of hyphae, and fruiting bodies were recovered from recently deposited sediments of the Luangwa River in Zambia. Twenty forms (36%) are comparable to the propagules of known living genera. The diversity of form and wall structure indicates the kinds of fungal palynomorphs which can be expected to withstand standard palynological techniques employed in the processing of fine grained siltstone and mudstone sediments. The known habitat and host preference of many of the identified forms can conceivably be used to deduce the environmental conditions of similar fossil fungal floras recovered from Neogene sediments. No new taxa are proposed.

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 Coopers or Gundlachs 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 (Coopers/Gundlachs 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.

Pollen of proteaceous-type from latest Cretaceous sediments, southeastern Australia

Abundant and diverse proteaceous-like triaperturate pollen from Campanian-Maastrichtian sediments in the Otway Basin, southeastern Australia are systematically documented and compared with pollen of extant Proteaceae. Segregation of fossil and extant pollen types has been effected on apertural characters of which six states have been identified. Apertures are colpoid, poroid or porate. Pores of Propylipollis Martin & Harris, 1974 conform with those of subfamilies Grevillioideae and Carnarvonioideae. Colpoids of Beaupreaidites Cookson emend. Martin, 1973, poroids of Lewalanipollis gen. nov., and pores of Cranwellipollis Martin & Harris, 1974 are represented in subfamilies Proteoideae and Persoonioideae. Pores of Proteacidites Cookson ex Couper, 1953 occur in subfamilies Proteoideae and Sphalmioideae. In the Otway Basin fossil record, triporate apertures appear earlier than tricolpoids, triporoids and biporates; and diversity levels of proteaceous pollen are higher than reported from elsewhere implying the ...

Middle Eocene terrestrial palynomorphs from the Dolime Minerals and Gulf Hammock quarries, Florida, U.S.A.

Abstract A small but diverse assemblage of pollen and spores recovered from marine sediments of the Avon Park Formation (middle Eocene) in west central Florida, represents the oldest land flora described from the state. Twenty-one pollen taxa from terrestrial plants, are identified from the Dolime Minerals and Gulf Hammock quarries. The presence of mangrove pollen associates such as Acrostichum, Nypa, and Pelliciera associated with seagrass macrofossils, combined with evidence from invertebrate fossils and sedimentary structures, suggest that the sediments of the Avon Park Formation, at these quarry sites, were deposited in a shallow marine lagoon, perhaps near the mouth of a river or stream in a protected area that had some tidal influence. This is the earliest report of terrestrial vegetation and near marine vegetation of Florida and documents the presence of a Florida landmass during middle Eocene time.

New species of the late Cenozoic fungal form‐genus mediaverrunites Jarzen & Elsik 1986 ex Nandi & Sinha 2007

Abstract New species of the fungal form-genus Mediaverrunites Jarzen & Elsik 1986 ex Nandi & Sinha 2007 are described from tropical to warm temperate Neogene strata. Mediaverrunites fournierii sp. nov. and Mediaverrunites magnus sp. nov. occur in the Lower Miocene of Colombia. Mediaverrunites invaginatus sp. nov. is from the Upper Miocene to Lower Pleistocene, offshore Louisiana. The form-genus is also represented by an apparently undescribed extant species occurring in recent sediment.

Pollen with viscin threads from the late cretaceous and Paleocene, Mérida Andes, Western Venezuela

Abstract Fossil pollen exhibiting viscin threads are reported from Upper Cretaceous and Paleocene deposits in western Venezuela. The sediments were deposited in a marginal marine environment in an area presently occupied by the northern flank of the Venezuelan Andes. The palynofloras are well preserved and diverse and provide insight into the ancient vegetation of Venezuela. Pollen-bearing viscin threads from the Upper Cretaceous Mito Juan Formation are assigned to the genus Colombipollis Sarmiento Pérez 1994. The pollen grains are tri(col)porate, normally quite smooth, and most often viewed in an oblate (flattened) state. The viscin threads are on the proximal and distal sides of the pollen and vary in length; they appear to have a simple morphology unlike the complex, ropelike threads seen on pollen of the Onagraceae and some other angiosperm families. All observations to date are made using a standard light microscope but more morphological detail could be revealed using scanning electron microscopy. The pollen exhibiting viscin threads from the Paleocene Los Cuervos Formation are clearly related to onagraceous types and are assigned to the genus Corsinipollenites Nakomen 1995. The pollen is triporate and the viscin threads originate from the polar regions of the pollen. They resemble pollen reported from Eocene to Miocene deposits in the southern hemisphere (Australia, New Zealand) although are smaller in overall dimensions. The Venezuelan pollen reported in this paper post date the earliest record of viscin threads in the Turonian of the eastern United States. They represent the first reported forms from the South American region. In modern plants the presence of viscin threads has been related to the development of highly specific plant-pollinator relationships; their presence in the Late Cretaceous and Paleocene in Venezuela may help constrain the timing of the origin of certain insect groups in this area.

Feeding habits of the mahogany glider: Palynological evidence

Abstract Palynology has proven an effective method in providing supportive and new information on the visitation/foraging habits of the mahogany glider (Petaurus gracilis) in coastal northern Queensland, Australia. Pollen constitutes at least 30% by volume of the maceral contents in six of the eight fecal and intestinal samples examined. Pollen counts indicate that Myrtaceae taxa and Xanthorrhoea are the most frequently visited flowers, but significant occurrences of Banksia pollen suggest that it may also have been foraged. Incidental occurrences of Acacia, GrevilleaJ Hakea, Asteraceae, Casuarina, Deplanchea, and Ilex confirm the presence of these taxa within the gliders habitat.

Structure and form ofaustral Cretaceous Normapolles-like pollen

Detailed analysis of breviaxial, tricolporate pollen from the Australian Upper Cretaceous reveals that Forcipites Dettmann & Jarzen, 1988, Gambierina Harris ex Stover & Partridge, 1973, emend., and Battenipollis gen. nov. are distinct in wall structure and aperture architecture from the Normapolles and Probrevaxones of the Northern Hemisphere. The parental source of the southern Normapolles-like pollen ranged across the Austro-Antarctic landmass during latest Cretaceous time, but probably evolved later than and independently of the northern taxa. Battenipollis is proposed for transcolpate, breviaxial pollen, and Gambierina is herein emended.

Palynology and mycology of organic clay balls accompanying mastodon bones—New Brunswick, Canada

Abstract Enigmatic clay balls accompanying a 37000-year-old skeleton of an American mastodon, and clayey nodules adhering to some of the bones, were examined for pollen and spores of plants and spores of fungi. The nodule assemblage of plant palynomorphs is dominated by pollen of Cyperaceae, that of clay ball by pollen of Pinaceae. Both the nodule and the clay ball asemblages of fungi are dominated by spores of Sordariales, which are predominantly dung-dwelling, and which commonly occur in lake and peat sediments. However, the clay ball fungi are relatively more numerous, taxonomically more diverse, and ecologically representative of a wide range of habitats. From palynological and mycological evidence, and the presence of even-sized fragments of wood, we suggest that the organic component of the clay ball is derived from plants consumed by, and contained within, the animal at the time of death.