Systematic Paleontology and Paleobiogeography of Invertebrate Macrofauna and Trace Fossils from the Mekelle Basin, Ethiopia

We measured and described two stratigraphic sections at Hagere-selam and Wukro to conduct a detailed analysis of marine invertebrate macrofossil and trace fossil assemblages within the Antalo Limestone of the Mekelle Basin. This study provides the first comprehensive systematic description, paleoenvironmental reconstruction, and paleobiogeographic analysis of benthic marine invertebrates and trace fossils from the Antalo Limestone Formation. Using a multi-method approach involving field observations, in-situ morphological description, lab-based microscopy, and comparative analysis with type specimens, 26 species were identified. Among these, Somalirhynchia giddiyata n. sp., Zeilleria cf. waiohipaensis , Loboidothyris hypocistis , Bihenithyris barringtoni , Dorsoplicathyris nepalensis nov. sp., Lacunaerhynchia palma , Mesomiltha pulchra , Regalilima sp., Cladocoropsis mirabilis , Millericrinina sp. indet., Digonioceras enayi , Phycodes cf. palmatus , Thalassinoides suevicus , and Rhizocorallium commune are recorded for the first time from the Jurassic of Northern Ethiopia. The fauna shows close affinities with central Saudi Arabian and Tethyan faunas, indicating a persistent shoaling of the sea floor (20–30 m depth) during deposition.