Early Miocene coral reef-associated bryozoans from Colombia. Part I: Cyclostomata, “Anasca” and Cribrilinoidea Cheilostomata

Paola Flórez,Emanuela Di Martino,Laís V Ramalho

doi:10.1017/jpa.2021.5

Abstract

AbstractThis is the first of two comprehensive taxonomic works on the early Miocene (ca. 23–20 Ma) bryozoan fauna associated with coral reefs from the Siamaná Formation, in the remote region of Cocinetas Basin in the La Guajira Peninsula, northern Colombia, southern Caribbean. Fifteen bryozoan species in 11 families are described, comprising two cyclostomes and 13 cheilostomes. Two cheilostome genera and seven species are new:Antropora guajirensisn. sp.,Calpensia caribensisn. sp.,Atoichos magnusn. gen. n. sp.,Gymnophorella hadran. gen. n. sp.,Cribrilaria multicostatan. sp.,Cribrilaria nixorn. sp., andFigularia bragain. sp. Eight species are identified only at genus level and remain in open nomenclature. Of the species found, 27% have erect colonies and 73% encrusting colonies. Both types contributed to the reef framework and produced sediment. The observed bryozoan diversity was higher in the barrier reefs than in the lagoonal patch reefs.UUID:http://zoobank.org/5c8468ef-31b0-4e7e-ba93-60a2e2f30b76.

Highlights

Within a generally high marine biodiversity (Jackson and Johnson, 2001; Buzas et al, 2002), bryozoan diversity in Cenozoic tropical latitudes was very high (Di Martino et al, 2017, 2019)
The purpose of this paper is to: (1) describe the bryozoan species associated with shallow coral reefs in the Siamaná Formation (Aquitanian, ca. 23–20 Ma), thereby contributing to knowledge of bryozoan assemblages in the Caribbean Basin; (2) estimate the role played by bryozoans in reefs from the Siamaná Formation; and (3) identify the biogeographical patterns
Because Steginoporella sensu stricto lacks a gymnocyst (Harmer, 1926, p. 268; Gordon, 1984, p. 56), we introduce this new genus, and we place it in the family Steginoporellidae owing to its close resemblance with those species of Steginoporella and Siphonoporella discussed above

Summary

Introduction

Within a generally high marine biodiversity (Jackson and Johnson, 2001; Buzas et al, 2002), bryozoan diversity in Cenozoic tropical latitudes was very high (Di Martino et al, 2017, 2019). Taxonomic studies of bryozoan faunas from the early Miocene are generally limited for the Caribbean/Gulf of Mexico region (e.g., Sandberg, 1962; Cheetham et al, 1999, 2007; Herrera-Cubilla and Jackson, 2014; Di Martino et al, 2017), the western Atlantic (e.g., Zágoršek et al, 2014; Ramalho et al, 2015, 2017, 2019), or the Indo-Pacific (e.g., Li, 1990; Guha and Gopikrishna, 2005, 2007; Di Martino and Taylor, 2014, 2015), and for the more thoroughly investigated Paratethys/Mediterranean Sea (e.g., Duvergier, 1920; Buge, 1973; Nikulina and Taylor, 2010; Vávra, 2012; Di Martino and Taylor, 2017)

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