Comparative morphotaxonomical affinities, redescription and cladistic analyses of ornithoid eggshells belonging to the oofamily Laevisoolithidae from the Late Cretaceous intertrappean beds of Anjar, Gujarat, India

ASHU KHOSLA; MARIELA SOLEDAD FERNÁNDEZ; LEONARDO SALGADO; ASHOK SAHNI

Historical Biology

Taylor and Francis Ltd.

Lugar: London; Año: 2020

0891-2963

We reevaluate fragmentary eggshells of avian affinities (ratite morphotype) from the Late Cretaceous Intertrappean beds of Anjar (District Kachchh, Gujarat), India in view of additional material and cladistic analysis. Previously, Anjar eggshells were encompassed in the oofamily Subtiliolithidae, however now the oofamily Subtiliolithidae has been reexamined as a junior synonym of the oofamily Laevisoolithidae. External surface of the eggshells is smooth to rugose, with unevenly distributed, sub-rounded tubercles; average eggshell thickness (467-491µm) characterized by two layers: 1) a well-differentiated mammillary layer (196.1µm), comprising conical, crystalline aggregates with petaloid wedges, and 2) a continuous spongy layer (274.58 µm, CL:ML, 1.3:1) divulges a squamatic zone. The eggshells have been compared with four oofamilies (Elongatoolithidae, Arriagadoolithidae, Prismatoolithidae and Laevisoolithidae). Shell microstructure is reliable with oofamily Laevisoolithidae, an ootaxon usually related with enantiornithid birds. Cladistic analysis performed on the eggshells are consistent with the avian kinships recognized based on macro, micro and ultrastructural features.