Supplementary information for Jones et al., 2021: \"Size and shape variation in the calcareous nannoplankton genus Braarudosphaera following the Cretaceous-Paleogene (K/Pg) mass extinction: clues as to its evolutionary success\"

Calcareous nannoplankton have been one of the dominant primary producers in the surface oceans since the late Triassic. The bolide impact at the Cretaceous-Paleogene (K/Pg) boundary ~66.0 Ma, led to the elimination of > 90% of nannoplankton species: the largest extinction event in their evolutionary history.  One of the few nannoplankton genera to survive the K/Pg mass extinction and even thrive in its aftermath was Braarudosphaera, which precipitates pentagonal calcite plates (pentaliths).  The only Braarudosphaera species to span the K/Pg boundary (B. bigelowii) is extant, and has formed geographically and temporally restricted “blooms” throughout geologic time. Four morphologically and genetically distinct cryptic species of B. bigelowii have been identified in the modern ocean. However, it is uncertain whether these cryptic species have disparate eco-physiological tolerances that have allowed them to adapt to varying environmental conditions. For the first time, we assess changes...