The problematic lingulate brachiopod Aulonotreta from the Ordovician (Dapingian–Darriwilian) of Baltoscandia

Z Zhang,L E Holmer,L Yue

doi:10.3176/earth.2019.15

Abstract

The enigmatic and aberrant lingulate brachiopod Aulonotreta antiquissima (Eichwald) from the Dapingian (Volkhov Stage) Toila Formation of northern Estonia and St Petersburg area (Historical Region ...

Highlights

The heavily ornamented, thick-shelled and strongly biconvex, lingulate brachiopod Aulonotreta differs strongly from most other lingulates and has hitherto been monotypic; the three species and subspecies that have been proposed are either junior synonyms or not congeneric
The object of this study is to re-describe Aulonotreta antiquissima based on new material, prepared with modern methods, and to draw comparisons with the new species Aulonotreta neptuni from the Darriwilian, Baltoscandian Kunda Stage on the northernmost part of the Island of Öland, southern Sweden
The poor preservation of the strongly fragmented and recrystallized material of Aulonotreta neptuni makes it difficult to compare it in detail with the much better preserved Baltic type species

Summary

INTRODUCTION

The heavily ornamented, thick-shelled and strongly biconvex, lingulate brachiopod Aulonotreta differs strongly from most other lingulates and has hitherto been monotypic; the three species and subspecies that have been proposed are either junior synonyms or not congeneric. The object of this study is to re-describe Aulonotreta antiquissima based on new material, prepared with modern methods, and to draw comparisons with the new species Aulonotreta neptuni from the Darriwilian, Baltoscandian Kunda Stage on the northernmost part of the Island of Öland, southern Sweden. This occurrence of Aulonotreta has long been known The specimens of Aulonotreta neptuni sp. nov. come from the Hälludden, Torp, Byrum and Enerum localities on Öland

METHODS

Discussion

Findings

DISCUSSION