Inat Repost BotFeb 27
https://inaturalist.org Observation of the Day for Feb 26, 2026: Algidia viridata bicolor [Arachnida], by user: sebastiandoak
[via @inatrepostbot]
https://www.inaturalist.org/observations/337191626
Charleston 7892, New Zealand
2026-02-02T22:21:00+13:00
Credit: (c) Sebastian Doak, some rights reserved (CC BY)
See more: https://www.inaturalist.org/projects/inat-observation-of-the-day
#inaturalist #inaturalistorg #citizenscience #algidiaviridatabicolor #algidiaviridatabicolor #charleston7892 #newzealand #arachnida #animals #arthropods #chelicerates #arachnids #harvestmen #armoredharvestmen #triaenonychidharvestmen
Inat Repost BotJan 7
https://inaturalist.org Observation of the Day for Jan 6, 2026: Mesothrombium [Arachnida], by user: jeremyhegge
[via @inatrepostbot]
https://www.inaturalist.org/observations/329851418
New South Wales, AU
2025-12-05T15:45:39+11:00
Credit: (c) jeremyhegge, some rights reserved (CC BY-NC)
See more: https://www.inaturalist.org/projects/inat-observation-of-the-day
#inaturalist #inaturalistorg #citizenscience #mesothrombium #mesothrombium #newsouthwales #au #arachnida #animals #arthropods #chelicerates #arachnids #mitesandticks #trombidiformmites #prostigs #velvetmiteschiggersandrelatives #velvetmites #truevelvetmites
Cosmic LibrarianJul 3, 2025

Meet the 'weird' sea spider that's mapping the evolution of eight-legged creatures

It's not easy to look at a sea spider and see an animal so representative of its kind that it may help scientists sort out the evolution of almost everything with eight legs. But that's the potential a new study finds in these spindly, strikingly strange bottom-dwellers.

#evolution #seaspider #chelicerates

https://phys.org/news/2025-07-weird-sea-spider-evolution-legged.html

Meet the 'weird' sea spider that's mapping the evolution of eight-legged creatures

It's not easy to look at a sea spider and see an animal so representative of its kind that it may help scientists sort out the evolution of almost everything with eight legs. But that's the potential a new study finds in these spindly, strikingly strange bottom-dwellers.

Phys.org
CellBioNewsFeb 19, 2025

#Arachnid #evolution redefined: Whole-#genome duplications and multiple land #colonizations.

#chelicerates #phylogenomics

https://phys.org/news/2025-02-arachnid-evolution-redefined-genome-duplications.html

Arachnid evolution redefined: Whole-genome duplications and multiple land colonizations

A recent paper provides an updated perspective on the evolutionary history of chelicerates—a diverse and ecologically significant group of arthropods that includes spiders, scorpions, mites, and horseshoe crabs.

Phys.org
Lukas VFN 🇪🇺Jul 14, 2024

500 million-year-old #fossil is the earliest branch of the #spiders' lineage https://arstechnica.com/science/2024/07/earliest-known-ancestors-of-scorpions-were-tiny-sea-beasts/

Lower #Ordovician synziphosurine reveals early euchelicerate diversity and evolution https://www.nature.com/articles/s41467-024-48013-w

"Some of S. abundantis’ anatomical features allow for a deeper understanding of the early #evolution of #chelicerates and may even link other fossil forms, whose relationships are still highly debated, to this group"

500 million-year-old fossil is the earliest branch of the spider’s lineage

A local fossil collector in Morocco found the specimen decades ago.

Ars Technica
Lukas VFN 🇪🇺May 14, 2024

#Discovery of the first ancestors of scorpions, spiders and horseshoe crabs https://phys.org/news/2024-05-discovery-ancestors-scorpions-spiders-horseshoe.html

Lower #Ordovician synziphosurine reveals early euchelicerate diversity and #evolution https://www.nature.com/articles/s41467-024-48013-w

"Measuring between 5 and 10 millimeters in size, it has been named #Setapedites abundantis. This animal makes it possible, for the first time, to trace the entire lineage of #chelicerates, from the appearance of the earliest #arthropods to modern #spiders, #scorpions and #HorseshoeCrabs"

Discovery of the first ancestors of scorpions, spiders and horseshoe crabs

Who were the earliest ancestors of scorpions, spiders and horseshoe crabs? A Ph.D. student from the University of Lausanne (Switzerland), with the support of a CNRS researcher, has identified a fossil that fills the gap between modern species and those from the Cambrian period (505 million years ago), solving a long paleontological mystery.

Phys.org
Lukas VFN 🇪🇺Mar 1, 2024

Living species of #DaddyLonglegs has two additional sets of underdeveloped eyes as embryos https://phys.org/news/2024-02-species-daddy-longlegs-additional-underdeveloped.html

#VestigialOrgans alter #fossil placements in an ancient group of terrestrial #chelicerates https://www.cell.com/current-biology/abstract/S0960-9822(24)00153-2

"While a fossilized specimen of a more ancient version of the #arachnid found in 2014 had an additional set of lateral eyes on the side of the head, the new study is the first to show evidence of more than one eye set in a living daddy longlegs species."

Living species of daddy longlegs has two additional sets of underdeveloped eyes as embryos

While some people may first associate daddy longlegs with, well, their long legs, researchers Guilherme Gainett and Prashant Sharma have been especially focused on the arachnids' eyes. In their paper published last week in the journal Current Biology, the researchers found that a living species of daddy longlegs has two additional sets of underdeveloped eyes as embryos, implying that the species diversified earlier in the evolutionary tree than scientists believed.

Phys.org