{{Short description|Extinct genus of algae}} {{Automatic taxobox | fossil_range = Ediacaran<br> ~{{long fossil range|635|551|ref=<ref name="Jiang2011">{{Cite journal | last1 = Jiang | first1 = G. | last2 = Shi | first2 = X. | last3 = Zhang | first3 = S. | last4 = Wang | first4 = Y. | last5 = Xiao | first5 = S. | title = Stratigraphy and paleogeography of the Ediacaran Doushantuo Formation (ca. 635-551 Ma) in South China | journal = Gondwana Research | volume = 19 | issue = 4 | pages = 831–849 | year = 2011 | doi = 10.1016/j.gr.2011.01.006 | bibcode = 2011GondR..19..831J }}</ref>}}{{period fossil range|Neoproterozoic|635|551}} | taxon = Thallophyca | authority = Zhang, 1989 | type_species = {{extinct}}'''''Thallophyca ramosa''''' | type_species_authority = Zhang, 1989 | subdivision_ranks = Species | subdivision = * {{extinct}}''T. ramosa'' <small>Zhang, 1989</small><ref name=Zhang1989/> * {{extinct}}''T. phylloformis'' <small>Zhang & Yuan, 1992</small><ref name="Yun1992"/> * {{extinct}}''T. corrugata'' <small>Zhang & Yuan, 1992</small><ref name="Yun1992"/> | synonyms = * '''''T. ramosa''''' ** {{extinct}}''T. simplicia'' <small>Zhang, 1989</small><ref name=Zhang1989/> }}
'''''Thallophyca''''' is a non-mineralized branching alga from the Ediacaran period of China. Two distinct species are known, ''T. ramosa'' and ''T. corrugata''.
== Discovery == Fossil material of ''Thallophyca'' was found in the Doushantuo Formation, Guizhou Province of South China and formally described in 1989.<ref name="Zhang1989">{{cite journal|last=Zhang|first=Yun|year=1989|title=Multicellular thallophytes with differentiated tissues from Late Proterozoic phosphate rocks of South China|journal=Lethaia|volume=22|issue=2|pages=113–132|doi=10.1111/j.1502-3931.1989.tb01674.x}}</ref>
== Etymology == The generic name ''Thallophyca'' derives from a truncated Greek word ''Thallus'', commonly used for algae; and ''phyc'', to mean "seaweed".<ref name="Zhang1989"/>
The specific name of ''T. ramosa'' derives directly from the Latin word of the same spelling, ''ramosa'', to mean "branched", in reference to the appearance of its branching thallus.<ref name="Zhang1989"/> The specific name of ''T. corrugata'' derives directly from the Latin words of the same spelling, ''corrugata'', to mean "wrinkly", in reference to the wrinkly appearance of the thallus. And the specific name of ''T. phylloformis'' derives from the Greek word ''phyllo'', to mean "leaf"; and the Latin suffix word ''-formis'', to mean "shape", in reference to the leaf-like shape of its thallus.<ref name="Yun1992">{{cite journal |last1=Yun |first1=Zhang |last2=Xun‐Lal |first2=Yuan |title=New data on multicellular thallophytes and fragments of cellular tissues from Late Proterozoic phosphate rocks, South China |journal=Lethaia |date=January 1992 |volume=25 |issue=1 |pages=1–18 |doi=10.1111/j.1502-3931.1992.tb01788.x}}</ref>
== Description == ''Thallophyca'' are ellipsoidal alga growing up to {{cvt|3.5|mm|2}} in height and {{cvt|20|mm|1}} in width, with the outer portions of their thallus being enlarged, with notable differentiation into an outer cortex and an inner medulla. <ref name="Xiao2004">{{Cite journal | last1 = Xiao | first1 = S. | last2 = Knoll | first2 = A. H. | last3 = Yuan | first3 = X. | last4 = Pueschel | first4 = C. M. | title = Phosphatized multicellular algae in the Neoproterozoic Doushantuo Formation, China, and the early evolution of florideophyte red algae | journal = American Journal of Botany | volume = 91 | issue = 2 | pages = 214–227 | year = 2004 | pmid = 21653378 | doi = 10.3732/ajb.91.2.214| doi-access = free }}</ref><ref name="Shang2022">{{cite journal |last1=Shang |first1=Xiaodong |last2=Liu |first2=Pengju |title=Diverse multicellular algae from the early Ediacaran Doushantuo chert nodules and their palaeoecological implications |journal=Precambrian Research |date=January 2022 |volume=368 |article-number=106508 |doi=10.1016/j.precamres.2021.106508}}</ref> The outer cells of the cortex are slightly elongated and spheroidal to polyhedral in shape, and oriented along the thallus, meanwhile the inner cells of the medulla diverge outwards in rows.<ref name="Shang2022"/> These inners cells are similar to pseudoparenchyma, due to their tightly packed nature.<ref name="Shang2022"/> Some specimens of ''Thallophyca'' also show possible reproductive cells within the thallus in the form of clustered islands of larger cells which may be cystocarps, sorus-like structures, and cavities, which are suggested to be similar to conceptacles.<ref name="Xiao2004"/>
Due to the overall appearance of ''Thallophyca'', it has been compared to extant forms of Coralline algae, and as such has been postured to be an early stem group corallinalean red alga.<ref name="Xiao2004"/><ref name="Shang2022"/> It was also most likely a benthic alga, inferred from how its lobate protrusions and tissues grew, which can be seen in the large lobes of ''Thallophyca'' specimens, which radiate from a centre point.<ref name="Shang2022"/>
== Taxonomy == To date, ''Thallophyca'' contains three valid species, and one invalid species, which are as follows:
{| class="wikitable sortable" !Species !Authority !Type locality !Notes !Refs |- |''Thallophyca ramosa'' |{{harvp|Zhang|1989}} |Doushantuo Formation, South China |{{yes|valid}} |Type species |<ref name="Zhang1989"/> |- |''Thallophyca simplicia'' |{{harvp|Zhang|1989}} |Doushantuo Formation, South China |{{no|invalid}} |Synonym of ''T. ramosa''. |<ref name="Zhang1989"/><ref name="Shang2022"/> |- |''Thallophyca corrugata'' |{{harvp|Zhang & Yuan|1992}} |Doushantuo Formation, South China |{{yes|valid}} | |<ref name="Yun1992"/> |- |''Thallophyca phylloformis'' |{{harvp|Zhang & Yuan|1992}} |Doushantuo Formation, South China |{{yes|valid}} | |<ref name="Yun1992"/> |}
== See also == * Thallophycoides * Ediacaran biota
==References== {{Reflist}}
{{Taxonbar|from=Q7709724}}
Category:Ediacaran life Category:Fossil algae Category:Fossil taxa described in 1989