Resumen de Smothered Scampi: Taphonomy of Lobsters in the Upper Cretaceous Bearpaw Formation, Southern Alberta
Phosphatic concretions, containing remains of the lobster Palaeonephrops browni (Whitfield), are described from the Upper Cretaceous Bearpaw Formation of southern Alberta. Two modes of burial are interpreted to have enhanced the preservation potential of the lobsters: (1) burial of remains by volcanic ash, and (2) burial of remains within burrows due to sediment injection during storms. The latter mode of burial is indicated for the majority of the specimens studied, suggesting that the exceptional preservation of Palaeonephrops, and probably some other fossil decapod taxa may have been more strongly influenced by their life-habits than previously assumed. Within-burrow preservation of lobster specimens also demonstrates that obrution is not only important for the preservation of faunal elements residing on the sea-floor, but can also bias the preservation of some deep infaunal taxa. Following rapid burial, the preservation potential of the lobster remains was further enhanced by virtue of its phosphate-bearing cuticle, upon which, early diagenetic phosphate cements were preferentially precipitated. Further phosphate precipitation resulted in the entombment of the remains within phosphatic concretions, further protecting them from destructive taphonomic processes.
