Palaeobiogeography and Evolutionary Patterns of the Larger Foraminifer \u3cem\u3eBorelis\u3c/em\u3e de Montfort (Borelidae)

The palaeobiogeography of the alveolinoid Borelis species reveals the evolutionary patterns leading to the two extant representatives, which occur in shallow‐water tropical carbonate, coral reef‐related settings. Type material and new material of fossil Borelis species, along with Recent specimens were studied to assess their taxonomic status, species circumscriptions (based on proloculus size, occurrence of Y‐shaped septula, and the index of elongation), palaeobiogeography and evolutionary dynamics. The species dealt with here are known from exclusively fossil (B. pygmaea, B. inflata, B. philippinensis, B. melo, B. curdica), and from fossil and modern (B. pulchra, B. schlumbergeri) specimens. For the first time, fossil and Recent Borelis specimens are illustrated via micro‐computed tomography scanning images. Depending on the occurrence of Y‐shaped septula, two lineages are distinguished. Deriving from the middle–upper Eocene Borelis vonderschmitti, the first lineage includes B. inflata, B. pulchra and B. pygmaea, lacking Y‐shaped septula. The first species bearing Y‐shaped septula is the Rupelian B. philippinensis of the western Indo‐Pacific. The westward migrants of B. philippinensis into the Mediterranean gave rise to B. melo (Aquitanian–Messinian) and B. curdica (Burdigalian–Tortonian). These two species became isolated from the Indo‐Pacific by the Langhian eastern closure of the Mediterranean basin and disappeared during the Messinian Salinity Crisis. Since the Tortonian, B. schlumbergeri, which descended from B. philippinensis, has inhabited the Indo‐Pacific along with B. pulchra. From the central Pacific Ocean, B. pulchra reached the Caribbean area before the early Piacenzian closure of the Central America seaway

Between a Pod and a Hard Test: The Deep Evolution of Amoebae

Amoebozoa is the eukaryotic supergroup sister to Obazoa, the lineage that contains the animals and Fungi, as well as their protistan relatives, and the breviate and apusomonad flagellates. Amoebozoa is extraordinarily diverse, encompassing important model organisms and significant pathogens. Although amoebozoans are integral to global nutrient cycles and present in nearly all environments, they remain vastly understudied. We present a robust phylogeny of Amoebozoa based on broad representative set of taxa in a phylogenomic framework (325 genes). By sampling 61 taxa using culture-based and single-cell transcriptomics, our analyses show two major clades of Amoebozoa, Discosea, and Tevosa. This phylogeny refutes previous studies in major respects. Our results support the hypothesis that the last common ancestor of Amoebozoa was sexual and flagellated, it also may have had the ability to disperse propagules from a sporocarp-type fruiting body. Overall, the main macroevolutionary patterns in Amoebozoa appear to result from the parallel losses of homologous characters of a multiphase life cycle that included flagella, sex, and sporocarps rather than independent acquisition of convergent features