''Berriasella'' is a discoidal evolute
perisphinctacean ammonite
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
, and type genus for the
neocomitid subfamily
Berriasellinae
Berriasellinae is a subfamily of very late Jurassic and very early Cretaceous perisphinctoid ammonites in the family Neocomitidae. Berriasellinae comprises generally compressed, evolute genera, typically with furcated ribbing, and in some a smo ...
. Its ribbing is distinct, consisting of both simple and bifurcated ribs that extend from the umbilical seam across the venter; its whorl section generally compressed, the venter more or less narrowly rounded. The species ''
Berriasella jacobi
''Berriasella jacobi'' is an extinct species of ammonite from the late Jurassic and early Cretaceous. Because of its unique stratigraphic position, it is used as an index fossil to determine the boundary of the Cretaceous and Jurassic periods. The ...
'' traditionally has been regarded an index fossil defining the base of the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
, however since 2016 this had been replaced by the first occurrence of ''
Calpionella alpina
''Calpionella'' is an extinct genus of calpionellid, a group of single celled eukaryotes. ''. Some authors regard ''B. jacobi'' as instead belonging to the genus ''
Strambergella.
''
''Berriasella'', named by Uhlig, 1905, is known from the late
Upper Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987.
In European lithostratigraphy, the name ...
,
Tithonian
In the geological timescale, the Tithonian is the latest age of the Late Jurassic Epoch and the uppermost stage of the Upper Jurassic Series. It spans the time between 152.1 ± 4 Ma and 145.0 ± 4 Ma (million years ago). It is preceded by the K ...
, to the early
Lower Cretaceous
Lower may refer to:
*Lower (surname)
*Lower Township, New Jersey
*Lower Receiver (firearms)
*Lower Wick
Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eight ...
,
Berriasian
In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago) ...
and has a fairly worldwide distribution.
[Paleobiology Database - ''Berriasella'']
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...
.org
Distribution
Fossils of ''Berriasella'' have been found in:
;Jurassic
*
Latady and
Himalia Ridge Formations, Antarctica
*
Los Molles Formation
The Los Molles Formation is a geologic formation of Early to Middle Jurassic age, located at northern and central part of Neuquén Basin at Mendoza Shelf in Argentina. It is overlain by the Niyeu–Lajas Formation.McIlroy et al., 2005
Descrip ...
, Argentina
*
Guasasa Formation
The Guasasa Formation is a geologic formation in Cuba. It is Tithonian to Early Valanginian
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma ...
, Cuba
*
Chia Gara Formation, Iraq
*
Muktinath
Muktinath is a Vishnu temple, sacred to both Hindus and Buddhists. It is located in Muktinath Valley at the foot of the Thorong La mountain pass in Mustang, Nepal. It is one of the world's highest temples (altitude 3,800 m). Within Hinduism, it ...
, Nepal
*
Punta Moreno Formation, Peru
*
Hajar Formation, Yemen
;Cretaceous
*
President Beaches Formation, Antarctica
*
Guchuochun Formation, China
*
Buenavista Breccia, Colombia
*
Stramberk Formation, Czech Republic
* France
*
Szentivánhegy Limestone, Hungary
*
Giumal Sandstone, India
*
Shal Formation, Iran
*
Chia Gara Formation, Iraq
*
Carbonera and
Taraises Formations, Mexico
*
Pieniny Limestone and
Rogozno Formation, Poland
*
Chigan Formation, Russia
*
Tollo and
Miravetes Formations, Spain
*
Dvuyakornaya Formation
Dvuyakornaya Formation is a geological formation from the Cretaceous period in Crimea, south of Yalta. Remains found there include: ammonites, such as '' Berriasella'', and brachiopod
Brachiopods (), phylum Brachiopoda, are a phylum of trochoz ...
, Ukraine
*
Hajar Formation, Yemen
References
Further reading
*
Perisphinctoidea
Ammonitida families
Index fossils
Tithonian first appearances
Early Cretaceous genus extinctions
Cretaceous ammonites
Jurassic ammonites
Ammonites of Asia
Cretaceous China
Fossils of China
Fossils of India
Fossils of Iraq
Fossils of Iran
Fossils of Nepal
Fossils of Yemen
Ammonites of Antarctica
Ammonites of Europe
Fossils of the Czech Republic
Cretaceous France
Fossils of France
Fossils of Hungary
Fossils of Poland
Cretaceous Russia
Fossils of Russia
Cretaceous Spain
Fossils of Spain
Fossils of Ukraine
Ammonites of North America
Jurassic Cuba
Fossils of Cuba
Jurassic Mexico
Cretaceous Mexico
Fossils of Mexico
Ammonites of South America
Jurassic Argentina
Cretaceous Argentina
Fossils of Argentina
Cretaceous Colombia
Fossils of Colombia
Jurassic Peru
Fossils of Peru
Fossil taxa described in 1905
{{Ammonitina-stub