Even thick sequences of sediments in marine depositional basins contain only limited segments of the record of chlorophyll diagenesis. Extracts from Pleistocene deep-sea sediments (Baker and Smith, 1973a) yielded extensive information concerning early chlorin transformations. Investigations of marine sediments of Pliocene and Miocene age resulted in the first reports of free base porphyrins occ...

Parasite-host associations among insects and mammals or birds are well attended by neontological studies [1]. An Eocene bird louse compression fossil [2, 3] and several flea specimens from Eocene and Oligocene ambers [4-8], reported to date, are exceptionally similar to living louse and flea taxa. But the origin, morphology, and early evolution of parasites and their associations with hosts are...

Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is...

the study area is situated in the middle part of the tabas block. it contains outcrops of rocks that formed along longitudinal faults in early cimmerian orogenic phase. the basin subsided along these faults from the late triassic to early cretaceous, which include two sedimentary cycles. a sedimentary cycle, related to upper triassic to bajocian is known as shemshak group. another sedimentary c...

A partial skeleton of a pleurosternid turtle (Paracryptodira), from the Jurassic-Cretaceous transition at Spanish locality Agreda (Moncayo Region, Soria Province), is presented here. Its par...

Parasites are common in modern ecosystems and are also known from the fossil record. One of the best preserved and easily recognisable examples of parasitism in the fossil record concerns isopod-induced swellings in the branchial chamber of marine decapod crustaceans. However, very limited quantitative data on the variability of infestation percentages at the species, genus, and family levels a...

Evolution of planktic organisms from benthic ancestors is commonly thought to represent unidirectional expansion into new ecological domains, possibly only once per clade. For foraminifera, this evolutionary expansion occurred in the Early-Middle Jurassic, and all living and extinct planktic foraminifera have been placed within 1 clade, the Suborder Globigerinina. The subsequent radiation of pl...

The fossil record of Ginkgo leaf and reproductive organs has been well dated to the Mid-Jurassic (170 Myr). However, the fossil wood record that can safely be assigned to Ginkgoales has not yet been reported from strata predating the late Early Cretaceous (ca. 100 Myr). Here, we report a new fossil wood from the Mid-Late Jurassic transition deposit (153-165 Myr) of northeastern China. The new f...

A paleomagnetic study of rocks from the northern foot of the Tien Shan and the southern border of the Dzungar Basin, east of Urumqi (44.2°N, 86.0°E), spanning ages from middle Jurassic to early Tertiary was carried out to constrain the tectonic evolution in central Asia since Mesozoic time. Five middle Jurassic sites reveal a remagnetized direction close to the present Earth field in geographic...