Abrytasites (Abrytusites) is an extinct genus of cephalopods belonging to the Ammonoidea subclass. The genus was named after the ancient Roman town of Abrittus, located near the present Bulgarian city of Razgrad. There are several described species of Abrytasites, including A. thieuloyi, A. julianyi, and A. neumayri. They are inflated, with constrictions, have rather thick ribs springing irregularly, singly or in pairs, from umbilical bullae. Their inner whorls closely resemble types species of Valdedorsella. This animal lived 125–136.4 million years ago during the Hauterivian and the Barremian in Europe and western Africa.
Kamerunoceras is an extinct cephalopod genus belonging to the ammonite family Acanthoceratidae, found in Upper Cretaceous formations of Africa, Europe and North and South America.
Anahamulina is an extinct ammonoid cephalopod genus from the Lower Cretaceous. Named by Hyatt, 1900.
Anahoplites is a genus of rather involute, compressed hoplitid ammonites with flat sides, narrow flat or grooved venters, and flexious ribs or striae arising from weak umbilicle tubercles that end in fine dense ventrolateral nodes. The elements of their sutures are short, wide and jaggedy. Specimens of Annahoplites have diameters typically in the range of 4–6 centimetres (1.6–2.4 in) although some with diameters of as much as 19 centimetres (7.5 in) have been reported. The genus lived during the Cretaceous, from the Middle to the late Albian.
Astiericeras is an ammonite from the Lower Cretaceous, the shell of which is evolute, stout; outer whorl with strong, well spaced, transverse ribs that cross smoothly over the broad venter; early whorls with lateral tubercles. The outer, mature whorl separates from the coil but hooks back quickly, referred to as a heteromorph.
Astieridiscus is an extinct lower Cretaceous ammonite. Its shell evolute, covered by dense, simple or branching, slightly flexuous ribs. The sides are slightly flattened, the venter rounded. No umbilical or other tubercles except on innermost whorl. Superficially resembles Olcostephanus.
Barremites is an ammonoid cephalopod genus belonging to the family Desmoceratidae, that lived during the Hauterivian and Barremian stages of the Early Cretaceous.
Crioceratites is an ammonite genus from the Early Cretaceous belonging to the Ancyloceratoidea.
Heteroceras is a Lower Cretaceous heteromorph ammonite belonging to the ancyloceratoidean family, Heteroceratidae.
Neocomites is a genus of ammonite from the Lower Cretaceous, Berriasian to Hauterivian, and type genus for the Neocomitidae.
Leymeriellidae is a family of Lower Cretaceous ammonites comprising rather small forms distinguished from Hoplitidae by their flattened and grooved ribs and virtual absence of umbilical tubercles. The family is derived from the Desmoceratidae. Leymeriella schrammeni anterior has evolved from Desmoceras keilhacki keilhacki.
Pseudohaploceras is a genus of desmosceratid ammonites from the Early Cretaceous; Valanginian to Albian epochs.
Puzosia is a genus of desmoceratid ammonites, and the type genus for the Puzosiinae, which lived during the middle part of the Cretaceous, from early Aptian to Maastrichtian. Sepkoski defines the range from Albian to Santonian. The generic name comes from the Serbian words "Puž" (snail) and "oce/ose" (axis), gaining its name from the shell's snail-like appearance.
Melchiorites is a desmoceratid ammonite genus included in the subfamily Puzosiinae. Member species are characterized by an essentially evolute shell in which the early whorls are smooth, with sinuous radial or oblique constrictions but in which later whorls have feeble intermediate ribs on the outer part of the sides and venter.
Spitidiscus is a genus of ammonites placed in the family Holcodiscidae.
Hamulina is an extinct ammonoid cephalopod genus belonging to the family Hamulinidae. These cephalopod were fast-moving nektonic carnivores. They lived during the Cretaceous period, Barremian age. The type species is Hamulina astieriana.
Hemihoplites is an extinct genus of ammonoid cephalopods belonging to the family Hemihoplitidae. These fast-moving nektonic carnivores lived in the Cretaceous period, from Hauterivian age to Barremian age.
Holcodiscidae is an ammonite family placed in the superfamily Desmoceratoidea.
The Acanthoceratinae comprise a subfamily of ammonoid cephalopods that lived during the Late Cretaceous from the latter early Cenomanian to the late Turonian
Vassil Tzankov Tzankov was a Bulgarian geologist and paleontologist. He is best known for his work on Upper Cretaceous ammonites and bivalves. Tzankov was head of Bulgarian Geological Survey from 1941 until 1944. In 1945 he became docent and in 1947 - professor, and was appointed to the paleontology chair at Sofia University "St. Kliment Ohridski". In the late 1950s Tzankov organized the launch and became the first editor and one of the principal authors of the multi-volume treatise "Fossils of Bulgaria". Contributors to the treatise included leading Bulgarian specialists in the field. He served as deputy director of the Geological Institute at the Committee for Geology and Mineral Resources in the period 1960-1966. From 1967 to 1982 Tzankov also served as head of the Department of Paleontology with the Geological Institute at the Bulgarian Academy of Sciences. In 1967 he was elected as a corresponding member of the Bulgarian Academy of Sciences.
