''Beresellaceae'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of organisms of uncertain affinity, sometimes placed within the

Metazoa Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hol ...

(multicellular animals), but tentatively assigned to the

green alga The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( ...

order

Dasycladales Dasycladales is an Order (biology), order of large unicellular green algae in the class Ulvophyceae. It contains two families, the Dasycladaceae and the Polyphysaceae. These single celled algae are from 2 mm to 200 mm long. They liv ...

. Beresellids were

cosmopolitan Cosmopolitan may refer to: Internationalism * World citizen, one who eschews traditional geopolitical divisions derived from national citizenship * Cosmopolitanism, the idea that all of humanity belongs to a single moral community * Cosmopolitan ...

and their fossils are found in strata ranging in age from the

late Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at million years ago ( Ma), to the beginning of the succeeding ...

to the

early Permian 01 or 01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * '01 (Richard Müller album), ''01'' (Richard Müller album), 2001 * 01 (Urban Zakapa album), ''01'' (Urban Zakapa album), 2011 * ''01011 ...

. Members of the family took the form of calcareous cylindrical tubes in diameter and up to in length. The tubes are single or (rarely) paired with an axial canal that is often replaced with clear

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

during fossilization. Classification is based on the distinctive two-layer walls and verticils (blind pores) branching outward from the cylindrical body. The organism likely was surrounded by a mucilaginous coating, preserved in fossils as transparent calcite cement. , no reproductive structures have been found for members of this group. Beresellids became important marine carbonate sediment producers in the middle Carboniferous, in association with various phylloid algae. They are thought to have favored shallow, sheltered

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

s. Local accumulations were sometimes extensive enough to be distinguished as beresellid

bafflestone Bafflestone is a type of carbonate rock. The Dunham Classification (Dunham, 1962) of limestones employed the term boundstone to encompass all carbonate rocks that exhibited any evidence of the original components being organically-bound together ...

packstone Under the Dunham classification (Dunham, 1962Dunham, R.J. (1962) Classification of carbonate rocks according to depositional texture. In: Classification of Carbonate Rocks (Ed. W.E. Ham), Am. Assoc. Pet. Geol. Mem., 1, 108–121.) system of limesto ...

, making this a rock-forming family of algae.

References

Paleozoic life Dasycladales Chlorophyta families {{Ulvophyceae-stub