Phylogeny and Taxonomic Revision of the Genus Promachocrinus Carpenter, 1879 (Echinodermata: Crinoidea: Antedonidae).

• Grant number: 24/19344-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2025
• End date: April 30, 2027
• Field of knowledge: Biological Sciences - Zoology - Taxonomy of Recent Groups
• Principal Investigator: Marcelo Veronesi Fukuda
• Grantee: Túlio Henrique Custódio de Souza
• Host Institution: Museu de Zoologia (MZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Crinoids are an emblematic group of marine invertebrates, represented by sea lilies and featherstars, with records dating from the Ordovician Period to the present. Promachocrinus Carpenter, 1879 is a genus of the family Antedonidae, endemic to Antarctic and sub-Antarctic islands, representing the most abundant crinoid in the Antarctic Ocean. Until 2023, Promachocrinus was considered a monotypic genus, with P. 'kerguelensis' Carpenter, 1879 represented by different recognized lineages and a broad distribution on the continent. McLaughlin et al. (2023), following DNA-based assessments, identified these different lineages as eight distinct species. However, the morphological limits among these species are unclear. As a result, generic diagnoses have been established, supported by a set of overlapping characteristics among species. Thus, it is not possible to delimit these taxa without the use of molecular tools, making an in-depth morphological reevaluation of the clade necessary to identify new phylogenetically informative characters, as well as to gain a new understanding of traditional characters. Therefore, the present project aims to test the monophyly of the genus Promachocrinus and propose hypotheses of relationship among the species using cladistic methodology, based on in-depth morphological studies. For this purpose, specimens deposited in Brazilian as well as foreign scientific collections will be analyzed. The material will be examined using modern techniques of crinoid taxonomic analysis, such as scanning electron microscopy and computed microtomography. This project is expected to contribute to the systematic understanding and taxonomic delimitation of the genus Promachocrinus. (AU)