The Currently Earliest Angiosperm Fruit from the Jurassic of North America

Angiosperms are the single most important plant group in the current ecosystem. However, little is known about the origin and early evolution of angiosperms. Jurassic and earlier traces of angiosperms have been claimed multiple times from Europe and Asia, but reluctance to accept these records remains. To test the truthfulness of these claims, palaeobotanical records from continents other than Europe and Asia constitute a crucial test. Here I document a new angiosperm fruit, Dilcherifructus mexicana gen. et sp. nov, from the Middle Jurassic of Mexico. Its Jurassic age suggests that origin of angiosperms is much earlier than widely accepted, while its occurrence in the North America indicates that angiosperms were already widespread in the Jurassic, although they were still far away from their ecological radiation, which started in the Early Cretaceous.

The Phalangopsidae crickets (Orthoptera, Grylloidea) of the Seychelles Archipelago: Taxonomy of an ecological radiation

The Phalangopsidae crickets (Grylloidea) of the Seychelles are examined following extensive field sampling on several main islands of the archipelago (Mahé, Silhouette, Praslin, La Digue). Despite the small area of these islands, six genera (12 species) are documented, including one new genus and five new species. The type species of the genus Seychellesia Bolivar, 1912 is transferred to the genus Paragryllodes Karny, 1909 as Paragryllodes nitidula (Bolivar, 1912) n. comb. The other species described in Seychellesia are transferred to the genus Seselia Hugel & Desutter-Grandcolas, n. gen., as Seselia longicercata (Bolivar, 1912) n. comb. and Seselia patellifera (Bolivar, 1912) n. comb. Two new species are also described in the genus Seselia Hugel & Desutter-Grandcolas, n. gen., Seselia coccofessei Hugel & Desutter-Grandcolas, n. gen., n. sp. (type species of the genus) and Seselia matyoti Hugel & Desutter-Grandcolas, n. gen., n. sp. The genera Phaeogryllus Bolivar, 1912 and Phalangacris Bolivar, 1895 are redescribed, including Phalangacris ferlegro Hugel & Desutter-Grandcolas, n. sp. and Phalangacris sotsote Hugel & Desutter-Grandcolas, n. sp. that are new to science. The genus Gryllapterus Bolivar, 1912 is redescribed and transferred from the Landrevinae (Gryllidae) to the Cachoplistinae (Phalangopsidae). New tribes are defined for the genus Paragryllodes (Paragryllodini Hugel & Desutter-Grandcolas, n. tribe) on the one hand, and for Seselia Hugel & Desutter-Grandcolas, n. gen., Phalangacris, Phaeogryllus and Gryllapterus (Seselini Hugel & Desutter-Grandcolas, n. tribe) on the other, using morphological characters and the results of molecular phylogenetic studies (Warren et al. 2019). Phaloria (Papuloria) insularis (Bolivar, 1912) (Phaloriinae) is redescribed and restricted to Mahé, and its calling song is documented for the first time, while Phaloria (Papuloria) bolivari Hugel & Desutter-Grandcolas, n. sp. is newly described from Silhouette. Identification keys are proposed for the genera of Seselini Hugel & Desutter-Grandcolas, n. tribe, and for the species of Seselia Hugel & Desutter-Grandcolas, n. gen. and Phalangacris. The confusion between the Mogoplistidae Ornebius succineus Bolivar, 1912 and the Phalangopsidae Heterotrypus succineus Bolivar, 1910 is discussed, and the name Subtiloria succineus (Bolivar, 1912) considered a nomen nudum.

The late blooming amphipods: global change promoted post-Jurassic ecological radiation despite Palaeozoic origin

The ecological radiation of amphipods is striking among crustaceans. Despite high diversity, global distribution and key roles in all aquatic environments, little is known about their ecological transitions, evolutionary timescale and phylogenetic relationships. It has been proposed that the amphipod ecological diversification began in the Late Palaeozoic. By contrast, due to their affinity for cold/oxygenated water and absence of pre-Cenozoic fossils, we hypothesized that the ecological divergence of amphipods arose throughout the cool Late Mesozoic/Cenozoic. We tested our hypothesis by inferring a large-scale, time-calibrated, multilocus phylogeny, and reconstructed evolutionary patterns for major ecological traits. Although our results reveal a Late Palaeozoic amphipod origin, diversification and ecological divergence ensued only in the Late Mesozoic, overcoming a protracted stasis in marine littoral habitats. Multiple independent post-Jurassic radiations took place in deep-sea, freshwater, terrestrial, pelagic and symbiotic environments, usually postdating deep-sea faunal extinctions, and corresponding with significant climatic cooling, tectonic reconfiguration, continental flooding, and increased oceanic oxygenation. We conclude that the profound Late Mesozoic global changes triggered a tipping point in amphipod evolution by unlocking ecological opportunities that promoted radiation into many new niches. Our study also provides a solid, time-calibrated, evolutionary framework to accelerate research on this overlooked, yet globally important taxon.

Non-reef environments impact the diversification of extant jacks, remoras and allies (Carangoidei, Percomorpha)

Various factors may impact the processes of diversification of a clade. In the marine realm, it has been shown that coral reef environments have promoted diversification in various fish groups. With the exception of requiem sharks, all the groups showing a higher level of diversity in reefs than in non-reef habitats have diets based predominantly on plankton, algae or benthic invertebrates. Here we explore the pattern of diversification of carangoid fishes, a clade that includes numerous piscivorous species (e.g. trevallies, jacks and dolphinfishes), using time-calibrated phylogenies as well as ecological and morphological data from both extant and fossil species. The study of carangoid morphospace suggests that reef environments played a role in their early radiation during the Eocene. However, contrary to the hypothesis of a reef-association-promoting effect, we show that habitat shifts to non-reef environments have increased the rates of morphological diversification (i.e. size and body shape) in extant carangoids. Piscivory did not have a major impact on the tempo of diversification of this group. Through the ecological radiation of carangoid fishes, we demonstrate that non-reef environments may sustain and promote processes of diversification of different marine fish groups, at least those including a large proportion of piscivorous species.