Data from: Palaeobiogeography and evolutionary patterns of the larger foraminifer Borelis 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.