Early Miocene coral reef-associated bryozoans from Colombia. Part II: “Ascophora” Cheilostomatida

Paola Flórez,Emanuela Di Martino,Laís V Ramalho

doi:10.1017/jpa.2021.94

Abstract

AbstractBryozoans are common and diverse in fossil and modern coral reefs. However, studies of bryozoans in ancient reefs are generally limited, and even less is known about fossil bryozoan faunas associated with coral reefs in the Caribbean region. This is the second contribution describing the bryozoan assemblage from the early Miocene (Aquitanian) reefs of the Siamaná Formation in the La Guajira Peninsula, southern Caribbean. Here, we describe and illustrate 17 species of ascophoran-grade cheilostomes, including one new genus and three new species,Ditaxiporina colombianan. sp.,Poricella paulaen. sp., andCycloavicularia parvan. gen. n. sp. Of the remaining fourteen taxa left in open nomenclature, one is considered confer and three affinis to species previously described, one is identified at family level, and nine at genus level. The Siamaná bryozoan fauna differs in species and colony-form composition from those associated with other paleoenvironments from Oligocene and Miocene localities of North America, the Caribbean, and Brazil.UUID:http://zoobank.org/043eadcf-0e39-4c1b-b207-f7628d6b5c84

Highlights

Shallow-water coral reefs are one of the most diverse ecosystems on Earth
The study area comprises patch reefs distributed in a shallow lagoon and in the discontinuous coral barrier enclosing the lagoon (Flórez, 2020)
These coral communities thrived in tropical waters, at depths of 2–30 m, with low turbidity, low energy, and limited siliciclastic input (Flórez et al, 2019a, b; Flórez, 2020)

Summary

Introduction

Shallow-water coral reefs are one of the most diverse ecosystems on Earth. Their structural framework provides a suitable habitat for diverse assemblages of organisms (Graham and Nash, 2013). Studies focused on bryozoans associated with coral reefs of this age are non-existent This is the second part of a comprehensive taxonomic study of the bryozoan fauna from the early Miocene deposits of the Siamaná Formation in Colombia, interpreted as shallow-water coral reefs (Flórez et al, 2019a, b). We follow Flórez (2020) and Flórez et al (2021) who suggested an early Miocene age based on larger benthic foraminifera, and the dating provided by Silva-Tamayo et al (2017) based on strontium isotopes of coralline algae from the same localities studied here. Additional information on the geologic and stratigraphic settings of the sampling localities is provided in Flórez et al (2019a, fig. 2)

Materials and methods

Pseudopore diameter

Findings

Discussion