Prolobitidae
Encyclopedia
Prolobitidae is a family of middle and upper Devonian
ammonoid cephalopods currently included in the goniatitid suborder Tornoceratina
and superfamily Dimeroceratoidea, but previously included in the ancestral Anarcestida.
Prolobitids are characterized by goniatic sutures with an undivided ventral lobe and primary lateral lobes that are introduced in the umbilical region. They have shells which are discoidal to subglobular, some bearing transverse ribs and the umbilicus is generally moderate to closed.
Prolobitidae is divided into two subfamilies, Prolobitinae
consisting of subglobular to subdiscoidal shells with moderate to closed umbilici, and Raymondoceratinae
consisting of discodal shells with tramsverse ribs and large umbilici.
The Prolobitidae have been considered the likely ancestors for Prolecanitida
.
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
ammonoid cephalopods currently included in the goniatitid suborder Tornoceratina
Tornoceratina
Tornoceratatina is one of two suborders of the Goniatitida order. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:...
and superfamily Dimeroceratoidea, but previously included in the ancestral Anarcestida.
Prolobitids are characterized by goniatic sutures with an undivided ventral lobe and primary lateral lobes that are introduced in the umbilical region. They have shells which are discoidal to subglobular, some bearing transverse ribs and the umbilicus is generally moderate to closed.
Prolobitidae is divided into two subfamilies, Prolobitinae
Prolobitinae
Prolobitinae is one of two subfamilies of the Prolobitidae family, a member of the Goniatitida order. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopodes, and cuttlefish, and more distantly to the nautiloids.-References:* accessed on...
consisting of subglobular to subdiscoidal shells with moderate to closed umbilici, and Raymondoceratinae
Raymondoceratinae
Raymondoceratinae is one of two subfamilies of the Prolobitidae family, a member of the Goniatitida order. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopodes, and cuttlefish, and more distantly to the nautiloids.-References:* accessed on...
consisting of discodal shells with tramsverse ribs and large umbilici.
The Prolobitidae have been considered the likely ancestors for Prolecanitida
Prolecanitida
The Prolecanitida are extinct ammonoid cephalopods with discoidal to thinly lenticular shells with goniatitic or ceratitic sutures and which retained the simple retrochoanitic siphuncle with backward extending septal necks. As typical for ammonoids the siphuncle is along the ventral margin...
.