Cenozoic history of the tropical marine biodiversity hotspot.

The region with the highest marine biodiversity on our planet is known as the Coral Triangle or Indo-Australian Archipelago (IAA). Its enormous biodiversity has long attracted the interest of biologists; however, the detailed evolutionary history of the IAA biodiversity hotspot remains poorly understood. Here we present a high-resolution reconstruction of the Cenozoic diversity history of the IAA by inferring speciation-extinction dynamics using a comprehensive fossil dataset.

Deciphering deterministic factors of predation pressures in deep time.

Predation pressure occurs as a result of predation frequency and prey vulnerability. Although quantifying these factors individually is essential to precisely understand predation effects on evolution, they have been generally less accessible. Here, using a modified form of Poisson function, we quantified the frequencies and vulnerabilities, as well as the resulting predation pressures, concerning the shell drillers versus prey interactions from the Eocene and Miocene periods.

A new species of false spider crab of the genus Elamena H. Milne Edwards, 1837 (Crustacea: Decapoda: Brachyura: Hymenosomatidae), from Davao Gulf, Philippines.

A new species of hymenosomatid crab of the genus Elamena H. Milne Edwards, 1837, is described from the island of Samal, in the Davao Gulf, Mindanao, southern Philippines. Elamena samalensis sp.

Permanent El Niño during the Pliocene warm period not supported by coral evidence.

The El Niño/Southern Oscillation (ENSO) system during the Pliocene warm period (PWP; 3-5 million years ago) may have existed in a permanent El Niño state with a sharply reduced zonal sea surface temperature (SST) gradient in the equatorial Pacific Ocean. This suggests that during the PWP, when global mean temperatures and atmospheric carbon dioxide concentrations were similar to those projected for near-term climate change, ENSO variability--and related global climate teleconnections-could have been radically different from that today. Yet, owing to a lack of observational evidence on seasonal and interannual SST variability from crucial low-latitude sites, this fundamental climate characteristic of the PWP remains controversial.

Color polymorphism and historical biogeography in the Japanese patellogastropod limpet Cellana nigrolineata (Reeve) (Patellogastropoda: Nacellidae).

Cellana nigrolineata is amongst the most common and largest patellogastropod limpets in Japan, and has two color morphs. Analyses of anatomical and morphological characters, shell structure, and mitochondrial COI data (658bp) of these color morphs suggested that they represent intraspecific genetic variation. Molecular analysis demonstrated that the species can be subdivided into three genetically distinct groups: (Clade 1) Honshu, Shikoku to Eastern Kyushu, (Clade 2) Western Kyushu and (Clade 3) Southern Kyushu.

A 5000-year fossil record of larval shell morphology of submarine cave microshells.

A 5000-year fossil series of minute submarine cave bivalves was studied using morphometric and evolutionary analyses. The obtained results indicate that the shapes of larval shells of studied species were labile, whereas the size of the larval shell was stable in each species studied. This result is different than that previously reported in most other studies in which size change is more common than shape change.

Major adaptive radiation in neritopsine gastropods estimated from 28S rRNA sequences and fossil records.

A well-supported phylogeny of the Neritopsina, a gastropod superorder archaic in origin, radiated ecologically and diverse in morphology, is reconstructed based on partial 28S rRNA sequences. The result (Neritopsidae (Hydrocenidae (Helicinidae + Neritiliidae) (Neritidae + Phenacolepadidae))) is highly congruent with the fossil records and the character distribution of reproductive tracts in extant taxa. We suggest that the Neritopsina originated in subtidal shallow waters, invaded the land and became fully terrestrial at least three times in different clades, by the extinct Dawsonellidae in the Late Palaeozoic and by the Helicinidae and Hydrocenidae in the Mesozoic.

A new species of Thetispelecaris (Crustacea: Peracarida) from submarine cave on Grand Cayman Island.

A new species of the peracaridan order Bochusacea, Thetispelecaris yurikago, is described from a submarine cave on Grand Cayman Island, the Caribbean Sea. The new species is the fourth species of the order and family, and the second of the genus. Recent studies have strongly suggested a close phylogenetic affinity between cave-dwelling and deep-sea taxa in the Bochusacea as recognized in other cavernicolous/deep-sea crustaceans such as amphipods and copepods.