Belongs within: Eugraptoloida.Contains: Isograptus, Bireclinata, Tetragraptinae . The Reclinata are a clade of graptoloids defined by Maletz et al. (2009) as the smallest clade including Tetragraptus serra and Exigraptus uniformis. Synapomorphies of the clade include the presence of a rutellum on the ventral side of the sicular aperture, serially homologous ventral projections on the proximal… Continue reading Reclinata
Category: Hemichordata
Climacograptus
Belongs within: Climacograptidae. Climacograptus is a genus of graptoloids known from the Lower Ordovician to Lower Silurian, with a biserial and nearly circular rhabdosome. The type species C. bicornis bears unusually large apertural spines, with the distal portions of the first two thecae often growing back along the spines (Bulman 1970). Characters (Bulman 1970): Rhabdosome nearly circular… Continue reading Climacograptus
Axonophora
Belongs within: Bireclinata.Contains: Neograptina, Dicranograptidae, Climacograptidae, Lasiograptidae, Orthograptinae. The Axonophora are a clade of graptoloids ancestrally defined by a biserial, dipleural rhabdosome, though a number of derived taxa became uniserial. The leading rod of the colony forms a nema that is followed by or engulfed in growth of the thecal rows (Maletz 2014). The clade… Continue reading Axonophora
Dicranograptidae
Belongs within: Axonophora. The Dicranograptidae are an Ordovician group of biserial graptoloids with a characteristic pattern of astogeny. The colony shape varies from multiramous to single-stiped, with some taxa showing cladial distal branchings. The slender Nemagraptinae derived from the paraphyletic ‘Dicranograptinae’ via changes in the proximal end of the colony (Maletz 2014). Characters (Maletz 2014): Biserial,… Continue reading Dicranograptidae
Monograptus
Belongs within: Monograptoidea. Monograptus has been recognised as a genus of uniserial graptoloids from the Lower Silurian to Lower Devonian. Monophyly of the genus is, however, uncertain, as it has been used to refer to all monograptids that lack cladia or characters of other monograptine genera (Bulman 1970). Ni & Jiao (1983) used the name… Continue reading Monograptus
Cephalodiscidae
Belongs within: Hemichordata. The cephalodiscids Published 25 September 2021 Among the more obscure inhabitants of the world’s oceans are the Cephalodiscidae, a family of small (only a few millimetres in length), largely sessile animals that mostly live in colonies within a shared domicile. Though rarely observed, cephalodiscids have received their fair share of attention due… Continue reading Cephalodiscidae
Bireclinata
Belongs within: Reclinata.Contains: Axonophora. In the arms of Pseudisograptus Published 25 April 2021 From the Ordovician to the early Devonian, the graptoloids were a major component of the oceanic fauna. These colonial floaters are among the characteristic fossils of the early Palaeozoic and have received a lot of attention due to their use in biostratigraphy.… Continue reading Bireclinata
Graptolithina
Belongs within: Hemichordata.Contains: Dithecodendridae, Rhabdopleuridae, Wimanicrustidae, Cyclograptidae, Dendroidea. The Graptolithina, graptolites, are a group of colonial organisms known from the Middle Cambrian to the Carboniferous that produced linear, branched or encrusting colonies. Further readings from the rocks Published 6 April 2009 Today, I’m going back to Graptolithina, the graptolites. For those of you who aren’t… Continue reading Graptolithina
Lasiograptidae
Belongs within: Axonophora. The Archiretiolitinae are a group of ‘retiolitid’ graptolites from the Upper Ordovician in which the initial part of the colony remains sclerotised, with the distal arms net-like. <==Lasiograptidae [Archiretiolitinae, Lasiograptinae] |–Hallograptus Lapworth 1876M14 | |–*H. bimucronatus (Nicholson 1869) [=Diplograpsus bimucronatus; incl. Graptolithus whitfieldi]B70 | |–H. inutilis (Hall 1865)R93 | `–H. mucronatusB70 |… Continue reading Lasiograptidae
Dendrograptus
Belongs within: Dendroidea. Dendrograptus is a long-lived genus of irregularly branching dendroid graptolites that is known from the Middle or Upper Cambrian to the Carboniferous (Bulman 1970). Characters (from Bulman 1970): Generally robust, shrublike in habit, branching irregularly, stipes usually divergent, unconnected, stem well developed, with basal attachment; autothecae denticulate, spined or with apertural processes.… Continue reading Dendrograptus