Venustulus
[1][3] Despite often being aligned close to horseshoe crabs, it has been found that Venustulus and its relatives form a group made up of various basal euchelicerate arthropods more distant to the xiphosurans.This arthropod appears to be blind due to the lack of eyes on its carapace, suggesting it lived either in deep water or buried in the sediments.[1] This creature was once considered the earliest known member of its grouping, however more recently synziphosuran fossils have been found in earlier Ordovician deposits.[1][8] This arthropods five-six pair of appendages contrasts the seven usually seen in other synziphosurans, possibly suggesting that this creature represents a more derived form than other members of its grouping.[10] Although the taxonomic relationships of Venustulus are still up for debate, the paper that described it noted that the arthropod has shared characteristics more similar to the weinberginid synziphosurans Weinbergina, Legrandella and Willwerathia.
SilurianTelychianPreꞒScientific classificationEukaryotaAnimaliaArthropodaChelicerataEuchelicerataProsomapodaType speciessynziphosurineparaphyleticcheliceratearthropodsFossilsdepositsperiodWisconsinUnited StatesWeinberginaAnderellaCamanchiahorseshoe crabseucheliceratexiphosuransWillwerathiacarapacetrilobitesOrdovicianWaukeshaParioscorpioThylacaresUW–Madison Geology MuseumprosomaopisthosomaBunodidaePseudoniscidaeWeinberginidaeLegrandellacheloniellidthylacocephalanphyllocaridsbutterfly animalannelidlobopodianschordatesconodontPanderodusbrachiopodscephalopodssnailscrinoidsspongesconulariidsBibcodeNatural History Museum BernPapers in Palaeontology