New mid-Cretaceous macrothelids showing a similar living mode to extant Macrothelidae (Araneae: Mygalomorphae)
Data files
Oct 15, 2024 version files 16.69 KB
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macrothelid_fossils_supplementary_files.zip
14.57 KB
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README.md
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Abstract
Five new spider species of the family Macrothelidae (Araneae: Mygalomorphae) are described from mid-Cretaceous Kachin amber, Myanmar. A new genus Acanthomacrothele gen. nov. is established for three new species: A. pauciverrucae sp. nov., A. geminata sp. nov. and A. longicaudata sp. nov. Both male and female specimens of A. pauciverrucae sp. nov. are described, representing a rare case of a fossil spider with both sexes known. We also describe an unidentified juvenile of Macrothelidae to document different developmental stages of Cretaceous species. To test the phylogenetic position of the new fossils, we performed phylogenetic analyses using both topology-unconstrained and topology-constrained methods. Our analyses supported the placement of Acanthomacrothele gen. nov. in Macrothelidae, although its phylogenetic relationship to other genera of Macrothelidae differed among different analytical methods. The fossils documented here have elongated, widely spaced posterior lateral spinnerets, compact rectangular group of eyes on a tubercle and more spines on male tibia of anterior legs than female, similar to extant macrothelids, suggesting that they probably have similar retreat construction behavior, habitat preference and mating position to their living relatives.
Description of dataset
This dataset comprises the raw data files and scripts supporting the article "New mid-Cretaceous macrothelids showing a similar living mode to extant Macrothelidae (Araneae: Mygalomorphae)". In this study, to test the phylogenetic position of the genera Acanthomacrothele and Promacrothele, we performed phylogenetic analyses using both topology-unconstrained and topology-constrained methods. Unconstrained phylogenetic analyses were carried out using maximum parsimony (MP), Bayesian inference (BI) and maximum-likelihood (ML) methods. Constrained phylogenetic analyses were carried out using MP and BI methods following Fikáček et al. (2020). Alternative placements of Promacrothele and Acanthomacrothele, and their posterior probabilities were calculated and visualized using the “showing_position_of_fossil_taxon.R” script using the complete set of posterior probability trees and the consensus tree as input data.
List of files:
Constrained_Matrix.nex (for constrained BI analyses in MrBays)
Constrained_Matrix.ss (for constrained MP analyses in TNT)
Constrained_Matrix_Acanthomacrothele.nex (for the analyses of alternative placements of Acanthomacrothele using BI method in MrBays)
Constrained_Matrix_Promacrothele.nex (for the analyses of alternative placements of Promacrothele using BI method in MrBays)
Reference_tree_WINCLADA.tre (reference tree used as a set of constraints built in WinClada)
Reference_tree_WINCLADA_numbered_taxa.tre (reference tree with numbered taxa used as a set of constraints built in WinClada)
showing_position_of_Acanthomacrothele.R (R script used in the analyses of alternative placements of Acanthomacrothele)
showing_position_of_Promacrothele.R (R script used in the analyses of alternative placements of Promacrothele)
Unconstrained_Matrix.nex (for unconstrained BI analyses in MrBays)
Unconstrained_Matrix.phy (for unconstrained ML analyses in IQ-TREE)
Unconstrained_Matrix.ss (for unconstrained MP analyses in TNT)