Two heterosporous plants from the Upper Devonian of North America

Chaloneria Gen. Nov.; Heterosporous Lycophytes from the Pennsylvanian of North America

Eoarthropleura ( Arthropoda , Arthropleurida ) from the Silurian of Britain and the Devonian of North America

Eoarthropleura, previously known only from the Lower Devonian of Germany, is reported here from the Upper Silurian (PHdoli) of Shropshire, England, the Upper Devonian (Frasnian) of New York State, USA, and the Lower Devonian (Emsian) of New Brunswick, Canada. The Shropshire form (E. ludfordensis n. sp.) is the earliest representative of the Arthropleurida. The New York species, originally ascri...

A Marine Stem-Tetrapod from the Devonian of Western North America

The origin of terrestrial vertebrates represents one of the major evolutionary and ecological transformations in the history of life, and the established timing and environment of this transition has recently come under scrutiny. The discovery and description of a well-preserved fossil sarcopterygian (fleshy-limbed vertebrate) from the Middle Devonian of Nevada helps to refine and question aspe...

Early land animals in north america: evidence from devonian age arthropods from gilboa, new york.

A new fossil site near Gilboa, New York, is one of only three where fossils of terrestrial arthropods of Devonian age have been found. The new Gilboan fauna is younger than the other two but richer in taxa. Fragmentary remains and nearly whole specimens assigned to Eurypterida, Arachnida (Trigonotarbida, Araneae, Amblypygi, and Acari), Chilopoda [Craterostigmatomorpha(?) and Scuterigeromorpha(?...

Herbivory and pollen limitation at the upper elevational range limit of two forest understory plants of eastern North America

Studies of species' range limits focus most often on abiotic factors, although the strength of biotic interactions might also vary along environmental gradients and have strong demographic effects. For example, pollinator abundance might decrease at range limits due to harsh environmental conditions, and reduced plant density can reduce attractiveness to pollinators and increase or decrease her...