The Amazonian rainforest is arguably the most species-rich terrestrial ecosystem in the world, yet the timing of the origin and evolutionary causes of this diversity are a matter of debate. We review the geologic and phylogenetic evidence from Amazonia and compare it with uplift records from the Andes. This uplift and its effect on regional climate fundamentally changed the Amazonian landscape by reconfiguring drainage patterns and creating a vast influx of sediments into the basin. On this “Andean” substrate, a region-wide edaphic mosaic developed that became extremely rich in species, particularly in Western Amazonia. We show that Andean uplift was crucial for the evolution of Amazonian landscapes and ecosystems, and that current biodiversity patterns are rooted deep in the pre-Quaternary.

/pdf/amazonia-through-time-andean-uplift-climate-change-landscape-438st0vlfu.pdf

Amazonia Through Time: Andean Uplift, Climate Change, Landscape Evolution, and Biodiversity

Amniote phylogeny and the importance of fossils

Human-induced stresses of overfishing, eutrophication, climate change, translocation and habitat modification appear to be promoting jellyfish (pelagic cnidarian and ctenophore) blooms to the detriment of other marine organisms. Mounting evidence suggests that the structure of pelagic ecosystems can change rapidly from one that is dominated by fish (that keep jellyfish in check through competition or predation) to a less desirable gelatinous state, with lasting ecological, economic and social consequences. Management actions needed to stop such changes require tactical coping strategies and longer-term preventative responses based on fundamental and targeted research on this understudied group.

/pdf/the-jellyfish-joyride-causes-consequences-and-management-1c27h0vbp7.pdf

The jellyfish joyride: causes, consequences and management responses to a more gelatinous future

– We present an updated classification for the entire Crustacea Decapoda, listing all known families and genera organized by higher taxonomic groups and including estimates of the number of species in every genus. All taxonomic names are also linked to the verified literature in which they were described, the first compilation of its kind for the Decapoda. To arrive at this compilation, we began with the classification scheme provided by Martin & Davis (2001) for extant families, updated the higher classification and included the fossil taxa. The resultant framework was then populated with the currently valid genera and an estimate of species numbers within each genus. Our resulting classification, spanning both extant (living) and fossil taxa, is the first comprehensive estimate of taxonomic diversity within the entire Decapoda. The classification consists of 233 families of decapods containing 2,725 genera and an estimated 17,635 species (including both extant and fossil species). Of the families in our classification, 53 are exclusively fossil, 109 contain both fossil and extant species, and 71 are extant only. The current estimate for extant species is 14,756, whereas 2,979 species are known exclusively as fossils.

A Classification of Living and Fossil Genera of Decapod Crustaceans

A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic relationships, based on evolutionary distances determined from pairwise comparisons of the 18S ribosomal RNA sequences. The classical Eumetazoa are divided into two groups. Cnidarians arose from a protist ancestry different from the second group, the Bilateria. Within the Bilateria, an early split gave rise to Platyhelminthes (flatworms) and the coelomate lineage. Coelomates are thus monophyletic, and they radiated rapidly into four groups: chordates, echinoderms, arthropods, and eucoelomate protostomes.

https://science.sciencemag.org/content/sci/239/4841/748.full.pdf

Molecular phylogeny of the animal kingdom

Santana Fossils: An Illustrated Atlas

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1096-0031.1986.tb00462.x

Heads and tails: a chordate phylogeny

Continental break up and the distribution of fishes of Western Gondwana during the Early Cretaceous

Higher elasmobranch phylogeny and biostratigraphy

Freshwater stingrays from the Fossil Butte Member of the late early Eocene Green River Formation of Wyoming are reviewed, and a new genus and species of fossil stingray is described. †Asterotrygon maloneyi, n.gen., n.sp. is remarkably well preserved and is known from articulated skeletons of juveniles and adults, both males and females. It is distinguished from all Recent and fossil stingrays, including †Heliobatis radians from the same formation, by the unique presence of a dorsal fin covered with dermal denticles directly anterior to the caudal stings. Other characters that in combination distinguish the new fossil genus from all other stingrays include: retention of separate, individual vertebrae extending to the tail extremity instead of a cartilaginous rod posterior to caudal stings; dorsal surface of disc and tail covered by numerous, closely packed, minute denticles; tail relatively stout at base; and relative proportions of disc and tail. †Asterotrygon, n.gen. shares with certain stingray...

Freshwater stingrays of the green river formation of wyoming (early eocene), with the description of a new genus and species and an analysis of its phylogenetic relationships (chondrichthyes: myliobatiformes)

John G. Maisey

Papers

Santana Fossils: An Illustrated Atlas

Heads and tails: a chordate phylogeny

Continental break up and the distribution of fishes of Western Gondwana during the Early Cretaceous

Higher elasmobranch phylogeny and biostratigraphy

Freshwater stingrays of the green river formation of wyoming (early eocene), with the description of a new genus and species and an analysis of its phylogenetic relationships (chondrichthyes: myliobatiformes)