A new Silurian (Llandoverian) biota from Wisconsin with a significant soft-bodied and lightly sclerotized component is dominated by arthropods worms. The fauna includes the earliest well-preserved xiphosure, possible marine uniramian, three of uncertain affinity, possibly first Paleozoic leech. This may be only second locality to yield conodont animal. Lack normal shelly suggests an unusual environment. discovery adds significantly few such exceptionally preserved faunas known Lower rocks.

Abstract Scorpions are among the first animals to have become fully terrestrialised. Their early fossil record is limited, and fundamental questions, including how when they adapted life on land, been difficult answer. Here we describe a new exceptionally preserved scorpion from Waukesha Biota (early Silurian, ca. 437.5–436.5 Ma) of Wisconsin, USA. This earliest yet reported, it shows combination primitive marine chelicerate derived arachnid characteristics. Elements circulatory,...

A new biota including lightly sclerotized and soft-bodied organisms occurs in finely laminated argillaceous dolomites of late Llandoverian age Waukesha County, Wisconsin. This discovery fills a gap between well known Cambrian Devonian Konservat Lagerstatten. The is dominated by arthropods. dalmanitid the most numerous 13 genera trilobites; crustaceans include phyllocarids ostracods; chelicerates are represented earliest preserved xiphosure fauna includes possible marine uniramian....

Thylacocephala is a group of enigmatic extinct arthropods. Here we provide full description the oldest unequivocal thylacocephalan, new genus and species Thylacares brandonensis, which present in Silurian Waukesha fauna from Wisconsin, USA. We also details younger, Jurassic specimens, Solnhofen lithographic limestones, are crucial to our interpretation systematic position Thylacocephala. In past, has been interpreted as crustacean ingroup closely related various groups such cirripeds,...

Abstract A relatively uncommon arthropod of the Waukesha lagerstätte, Parioscorpio venator , is redescribed as an bearing a combination characters that defy ready classification. Diagnostic features include sub‐chelate ‘great appendages’, lack antennae, multiramous anterior trunk appendages, filamentous fan‐like rear and apparently thin poorly preserved pleural fields. Phylogenetic analysis resolves this organism basal to crown‐group Mandibulata Chelicerata, but its exact placement...

The trilobite faunas found in carbonate buildups throughout much of the Paleozoic are remarkably similar both composition and general morphological characteristics. This is primarily result domination these by a limited number families which long-ranging buildup environment. Illaenids dominant trilobites Ordovician-Devonian generally accompanied members Lichidae Cheiruridae. Proetid characteristic Ordovician-Permian but seldom common. highest late Ordovician, with most important persisting...

Noncalcified thalli, consisting of a narrow main axis with numerous branched hairlike laterals in whorls and subapical array undivided clavate laterals, from the Silurian (Llandovery) Brandon Bridge Formation southeastern Wisconsin, constitute basis for new genus species dasycladalean alga, Heterocladus waukeshaensis. A relationship within family Triploporellaceae is indicated by whorled arrangement absence gametophores on mature specimens. compilation occurrence data suggests that...

A new synziphosurine (Chelicerata:Xiphosura) is described from the Late Llandovery (Silurian) Konservat-Lagerstätte of Waukesha, Wisconsin, USA. Venustulus waukeshaensis n.gen. and sp. characterized by a semicircular carapace with slightly procurved posterior margin lacking genal spines an opisthosoma composed 10 freely articulating segments, divided into preabdomen seven segments blunt pleurae postabdomen three pleurae. The tail spine short styliform. This earliest known unequivocal...

It is difficult to overestimate the importance of arthropods in history life. In terms diversity and abundance, modern embody ultimate success metazoa. Their prominence stems from an innovative, durable body plan, allowing mobility adaptability for almost any environment earth's biosphere. Arthropods have been able exploit enormous range lifestyles, becoming a conspicuous biotic component many marine terrestrial settings.

Abstract: Desmograptus micronematodes from Thornton quarry, Cook County, Illinois, USA, remarkably preserved in relief and encased pyrite, is described. The internal details of the thecae, stolon system, examined using SEM, allow reconstruction growth a stipe. stolons stolonal nodes are formed dense crassal fabric, surrounded by loose fabric three‐dimensional fibrils. have complex structure three boxes with proximal distal nozzles. base bitheca, each autothecal cup, has central nozzle unique...

Conodont biostratigraphy developed in 1994-1998 based on recovery and identification of many elements species recognized as Pterospathodus celloni, pennatus, amorphognathoides, other typical the celloni amorphognathoides Zones.

The Silurian Waukesha Lagerstätte of Wisconsin, USA, hosts a fauna distinctive soft-bodied organisms, including range graptolites, worms, trilobites and uncommon arthropods, but otherwise lacks most the shelly typical contemporaneous deposits. While several species have been described, much biota remains understudied. Here, we examine numerous specimens previously unnamed undescribed vermiform arthropod that bears cephalic carapace, suite specialized head appendages, long, segmented trunk,...

Although there is a relatively robust fossil record of archaeostracan phyllocarids, preserved antennulae and antennae are rare. Few examples have been described. A review archaeostracans with provided, as well description specimen Ceratiocaris cf. macrouraCollette Rudkin, 2010, antennae, detailed papilio Salter in Murchison, 1859, from the Silurian Scotland. The presence two subequal length rami Rhinocaridina Echinocaridina supports previous assertions that possessing biramous malacostracan...

The Wilhelmi Formation of Illinois and the Mosalem Iowa contain monospecific assemblages stratigraphically important species Normalograptus parvulus Lapworth. This is confined elsewhere to uppermost Ordovician persculptus Biozone lower part lowermost Silurian Parakidograptus acuminatus Biozone. presence this graptolite raises possibility that parts formations are late age rather than early as previously thought.

Silurian (Llandovery–Ludlow) Encrinurinae from Wisconsin, Indiana, and Illinois include species of Balizoma Holloway, 1980, Curriella Lamont, 1978, Distyrax Lane, 1988, Encrinurus Emmrich, 1844, Mackenziurus Edgecombe Chatterton, 1990a, Nucleurus Ramsköld, 1986. lauriae n. sp. is described Wenlock strata the Racine Sugar Run Dolomites; nine segments in holaspid thorax are fewest known for any encrinurid. A square rostral plate diagnostic . New morphological data provided by specimens...

Silurian trilobites of the central United States belong to a series temporally-successive associations which appeared abruptly, maintained taxonomic stasis for time, and then disappeared abruptly. Their disappearance resulted from global perturbations short-term duration moderate magnitude, caused substantial replacement but no reorganization major ecosystems. The most significant extinction in trilobite study area occurs near Llandovery–Wenlock boundary. This turnover appears correspond...