''Siberion'' 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 ...
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
lobopodian
Lobopodians are members of the informal group Lobopodia (), or the formally erected phylum Lobopoda Cavalier-Smith (1998). They are panarthropods with stubby legs called lobopods, a term which may also be used as a common name of this group as w ...
from the
Sinsk biota of
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
. Its anatomy, including the proboscis-like organ projecting from the face and prominent grasping first pair of appendages, suggests that xenusians like this organism may have been
phylogenetically
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...
related to
anomalocaridids
''Anomalocaris'' (from Ancient Greek , meaning "unlike", and , meaning "shrimp", with the intended meaning "unlike other shrimp") is an extinct genus of Radiodonta, radiodont, an order (biology), order of early-diverging stem-group marine arthrop ...
, like ''
Anomalocaris
''Anomalocaris'' (from Ancient Greek , meaning "unlike", and , meaning "shrimp", with the intended meaning "unlike other shrimp") is an extinct genus of radiodont, an order of early-diverging stem-group marine arthropods.
It is best known fro ...
''.
Only two incomplete specimens are known, and the probability of finding more is low, as the Sinsk Algal Lens has been nearly destroyed by commercial fossil collectors.
[
]
Morphology
It is similar to other siberiids, however it is distinguished by the shape of its “tail” and body. The holotype preserves most of the body, however the appendages and head are incomplete. Its body is annulated, and while the head preserves large appendages and a radial mouth further details are unclear. ''Siberion'' has at least 12 pairs of legs which may have gill branches like other siberiids, however as mentioned previously they are incomplete. At the posterior end there is a bulbous structure, which is likely an extension of the body due to similar muscle impressions. The only internal structure seen is the digestive tract which resembles that of dinocaridids, however it is unclear whether gut diverticulae are present.[
]
References
{{Taxonbar, from=Q7507030
Xenusia
Lobopodia
Cambrian genus extinctions