Hydroclimate variability in the Caribbean during North Atlantic Heinrich cooling events (H8 and H9).

We present a speleothem record from western Cuba, spanning the period 98.7-84.9 ka BP.

Northeast Yucatan hurricane activity during the Maya Classic and Postclassic periods.

The collapse of the Maya civilization in the late 1st/early 2nd millennium CE has been attributed to multiple internal and external causes including overpopulation, increased warfare, and environmental deterioration. Yet the role hurricanes may have played in the fracturing of Maya socio-political networks, site abandonment, and cultural reconfiguration remains unexplored. Here we present a 2200 yearlong hurricane record developed from sediment recovered from a flooded cenote on the northeastern Yucatan peninsula.

Paleoindian ochre mines in the submerged caves of the Yucatán Peninsula, Quintana Roo, Mexico.

Investigations in the now-submerged cave systems on the Yucatán Peninsula continue to yield evidence for human presence during the Pleistocene-Holocene transition. Skeletal remains are scattered throughout the caves of Quintana Roo, most representing individuals who died in situ. The reasons why they explored these underground environments have remained unclear.

An Assessment of Sub-Meter Scale Spatial Variability of Arcellinida (Testate Lobose Amoebae) Assemblages in a Temperate Lake: Implications for Limnological Studies.

Arcellinida (testate lobose amoebae), a group of benthic protists, were examined from 46 sediment-water interface samples collected from oligotrophic Oromocto Lake, New Brunswick, Canada. To assess (1) assemblage homogeneity at a sub-meter spatial scale and (2) the necessity for collecting samples from multiple stations during intra-lake surveys; multiple samples were collected from three stations (quadrats 1, 2, and 3) across the north basin of Oromocto Lake, with quadrat 1 (n = 16) being the furthest to the west, quadrat 2 (n = 15) situated closer to the center of the basin, and quadrat 3 (n = 15) positioned 300 m south of the mouth of Dead Brook, an inlet stream. Results from cluster analysis and non-metric multidimensional scaling (NMDS) analysis identified two major Arcellinida assemblages, A1 and A2, the latter containing two sub-assemblages (A2a and A2b).

Autoecological approaches to resolve subjective taxonomic divisions within arcellacea.

Arcellacea (testate lobose amoebae) are important lacustrine environmental indicators that have been used in paleoclimatic reconstructions, assessing the effectiveness of mine tailings pond reclamation projects and for studying the effects of land use change in rural, industrial and urban settings. Recognition of ecophenotypically significant infra-specific 'strains' within arcellacean assemblages has the potential to enhance the utility of the group in characterizing contemporary and paleoenvironments. We present a novel approach which employs statistical tools to investigate the environmental and taxonomic significance of proposed strains.