Data from: The oldest turritelline gastropods: from the Oxfordian (Upper Jurassic) of Kutch, India

Turritellid gastropods are important components of many Cretaceous-Recent
fossil marine faunas worldwide. Their shell is morphologically simple,
making homoplasy widespread and phylogenetic analysis difficult, but
fossil and living species can be recognized based on shell characters. For
many decades, it has been the consensus that the oldest definite
representatives of Turritellidae are from the lower Cretaceous, and that
pre-Cretaceous forms are homeomorphs. Some morphological characters of the
present turritelline species resemble those of mathildoids, but many
diagnostic characters clearly separate these two groups. We here describe
and/or redescribe – based on examination of more than 1800 near complete
specimens -- four species from the Upper Jurassic Dhosa Oolite Member of
the Chari Formation in Kutch, western India, and demonstrate that they are
members of Turritellidae, subfamily Turritellinae, on the basis of
diagnostic characters including apical sculptural ontogeny (obtained from
SEM study), spiral sculpture, and growth line patterns. The four species
are in order of abundance, Turritella jadavpuriensis Mitra and Ghosh,
1979; Turritella amitava new species; Turritella jhuraensis Mitra and
Ghosh, 1979 and Turritella dhosaensis new species. The turritelline
assemblages occur only on the northeastern flank of the Jhura dome
(23°24’47.57”N, 69°36’09.26”E). Age of the Dhosa Oolite has recently been
confirmed based on multiple ammonite species. All these points indicate
that these fossils are the oldest record of the family Turritellidae – by
almost 30 million years – in the world.