SILURIAN AND DEVONIAN MODIOMORPHIDAE BIVALVES FROM BOLIVIA

Division Rhyniophyta - Upper Silurian to Middle Devonian

Among the oldest convincing fossils of early vascular land plants are those of the Division Rhyniophyta. The members of this division consist of: (1) simple axes with cuticle, stomates, epidermis, cortex and a terete (circular) centrarch xylem (xylem development occurs from the center of the stem to the periphery), without well-developed appendages or roots; (2) simple, isotomous branching syst...

Phylogeny, classification and evolution of Silurian and Devonian scorpions

The phylogenetic position of scorpions within the Chelicerata has been the subject of much debate in recent years (e.g. Weygoldt & Paulus, 1979; Bergström, 1980; Van der Hammen, 1989; Shultz, 1990; Starobogatov, 1990), but it revolves around one primary question: are scorpions part of a monophyletic Arachnida, or are they “merostomes” which exhibit a terrestrial grade of existence? Inclusion of...

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...

Running head : Lower Devonian Nematothallus and Cosmochlaina anatomy Compression fossils from the Silurian and Devonian of southern Britain, composed of cuticles

The Influence of Silurian-Devonian Climates on the Rise of Air-Breathing Vertebrates.

beyond what was laid down by the rivers in time of flood to maintain their grade across the sinking basins was carried through to the shallow sea which lay on the surface of the continent to the southwest. The relations were somewhat similar to those which now prevail between the ranges of the North American Cordillera and the Tertiary basins which lay between them and especially on the west be...