Copepods are aquatic microcrustaceans and represent the most abundant metazoans on Earth, outnumbering insects and nematode worms. Their position of numerical world predominance can be attributed to three principal radiation events, i.e. their major habitat shift into the marine plankton, the colonization of freshwater and semiterrestrial environments, and the evolution of parasitism. Their variety of life strategies has generated an incredible morphological plasticity and disparity in body form and shape that are arguably unrivalled among the Crustacea. Although their chitinous exoskeleton is largely resistant to chemical degradation copepods are exceedingly scarce in the geological record with limited body fossil evidence being available for only three of the eight currently recognized orders. The preservation of aquatic arthropods in amber is unusual but offers a unique insight into ancient subtropical and tropical ecosystems. Here we report the first discovery of amber-preserved harpacticoid copepods, represented by ten putative species belonging to five families, based on Early Miocene (22.8 million years ago) samples from Chiapas, southeast Mexico. Their close resemblance to Recent mangrove-associated copepods highlights the antiquity of the specialized harpacticoid fauna living in this habitat. With the taxa reported herein, the Mexican amber holds the greatest diversity of fossil copepods worldwide.
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http://dx.doi.org/10.1038/srep34872 | DOI Listing |
J Anat
January 2025
Department of Earth Sciences, University College London, London, UK.
Argochampsa krebsi is a gavialoid crocodylian from the early Paleogene of North Africa. Based on its recovered phylogenetic relationship with South American species, it has been inferred to have been capable of transoceanic dispersal, but potential anatomical correlates for a marine lifestyle have yet to be identified. Based on CT scans of a mostly complete and well-preserved skull, we reconstruct the endocranial anatomy of Argochampsa and compare it to that of other gavialoids.
View Article and Find Full Text PDFPlant Divers
November 2024
CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu, Sichuan 610041, China.
The Indo-Burma Biodiversity Hotspot is renowned for its rich biodiversity, including that of vascular plants. However, the fern diversity and its endemism in this hotspot have not been well understood and so far, the diversity of very few groups of ferns in this region has been explored using combined molecular and morphological approaches. Here, we updated the plastid phylogeny of the Java fern genus with 226 (115% increase of the latest sampling) samples across the distribution range, specifically those of three phylogenetically significant species, , .
View Article and Find Full Text PDFMol Phylogenet Evol
January 2025
Autonomous University of Barcelona, Systematics and Evolution of Vascular Plants (UAB) - Associated Unit to CSIC by IBB - Cerdanyola del Vallès, Spain.
Widely distributed plant genera offer insights into biogeographic processes and biodiversity. The Carduus-Cirsium group, with over 600 species in eight genera, is diverse across the Holarctic regions, especially in the Mediterranean Basin, Southwest Asia, Japan, and North America. Despite this diversity, evolutionary and biogeographic processes within the group, particularly for the genus Cirsium, remain underexplored.
View Article and Find Full Text PDFMol Phylogenet Evol
December 2024
SNSB-Zoologische Staatssammlung München, Münchhausenstraße 21, D-81247 Munich, Germany; GeoBio-Center, Ludwig-Maximilians-University, Richard-Wagner-Straße 10, D-80333 Munich, Germany.
Disjunct distributions, characterised by spatially separated populations of related species, offer insights into historical biogeographic patterns and evolutionary processes. This study investigates the evolutionary history of the diving beetle subfamily Lancetinae through a phylogenomic approach incorporating ultraconserved elements (UCEs) and heritage genetic markers. Our findings support an early Miocene origin for Lancetinae, with subsequent diversification influenced by historical vicariance events and long-distance dispersal.
View Article and Find Full Text PDFProc Biol Sci
December 2024
Department of Zoology, University of Cambridge CB2 3EJ, UK.
Shrews are among the most speciose of mammalian clades, but their evolutionary history is poorly understood. Their fossil record is fragmentary and even the anatomy of living groups is not well documented. Here, we incorporate the oldest, most complete fossil shrew yet known into the first phylogenetic analysis of the group to include molecular, morphological and temporal data.
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