LAUSR

Abstract Turritella abrupta (Miocene-Pliocene) is the largest species known from the diverse Jurassic-Recent gastropod family Turritellidae. In addition to having achieved long length and substantial width, the species produces shells of exceptional thickness, even before secondary shell deposition. We investigated the paleoecology of this species through analysis of drilling and peeling frequencies with comparisons to co-occurring turritellid species. We used oxygen isotopic sclerochronology to infer the growth rate and lifespan of T. abrupta and to make comparisons with other modern and fossil tropical species, including the living species Turritella terebra, with the first sclerochronologies for both of these species presented herein. We find that T. abrupta was fast-growing, long-lived, and comparatively effective at resisting predation. T. abrupta was notably widespread geographically and temporally, but was a relatively rare component of faunas when compared with co-occurring turritellids. High rates of shell carbonate construction (in excess of 35 g in the first year of life) likely depended on habitats conducive to calcification. Late Miocene cooling and eastern Pacific carbonate limitation are implicated in the range contraction and eventual extinction of this species.