A NEW GENUS AND SPECIES OF CHAPERIIDAE (BRYOZOA: CHEILOSTOMATA) FROM THE EARLY MIOCENE OF PATAGONIA (ARGENTINA)

Authors

  • Juan López-Gappa División Invertebrados Museo Argentino de Ciencias Naturales
  • Leandro Martín Pérez División Paleozoología Invertebrados Museo de La Plata

DOI:

https://doi.org/10.5710/AMGH.30.08.2019.3281

Keywords:

Aluis spinettai, Bryozoa, Chaperiidae, Early Miocene, Monte León Formation, Chenque Formation, Argentina

Abstract

The family Chaperiidae reaches its highest biodiversity in the southern hemisphere. The main morphological feature characterizing the family is a pair of calcareous laminar structures associated with the insertion of the operculum occlusor muscles. The aim of this study is to describe Aluis spinettai gen. et sp. nov., from material collected in the Monte León, the Chenque, and the Puesto del Museo formations (early Miocene, Patagonia, Argentina). A. spinettai has erect bilaminar colonies, crenulated sutures between zooids, an extensive cryptocyst and spherical ovicells; gymnocyst, oral spines, and avicularia are absent. The new species exhibits a remarkable morphological convergence with a species of Aspidostoma from the early Miocene (Chenque Formation) of Patagonia. In some areas of the colony, the cryptocysts were pierced by circular drill holes made by an unknown predator. The stratigraphic distribution of A. spinettai ranges from ~19 to 17 Ma (Burdigalian). Its presence suggests a correlation between the upper levels of the Monte León Formation and the lower levels of the Chenque Formation. The paleogeographic distribution of this new species spans at least 500 km along the southern Atlantic coast of South America. The living representatives of the Chaperiidae in the Southwest Atlantic do not seem related to A. spinettai. doi: 10.5710/AMGH.30.08.2019.3281

Published

2019-12-21

Issue

Section

Articles

How to Cite

A NEW GENUS AND SPECIES OF CHAPERIIDAE (BRYOZOA: CHEILOSTOMATA) FROM THE EARLY MIOCENE OF PATAGONIA (ARGENTINA). (2019). Ameghiniana, 56(5), 422-429. https://doi.org/10.5710/AMGH.30.08.2019.3281