Xandarella

{{short description|Genus of arthropods (fossil)}}

{{Automatic taxobox

| fossil_range = {{Fossil range|Cambrian stage 3}}

| image = Xandarella.png

| image_caption = Drawing of X. spectaculum

| display_parents = 3

| taxon = Xandarella

| authority = Hou et al. 1991

| type_species = Xandarella spectaculum

| type_species_authority = Hou et al. 1991

}}

Xandarella is an extinct genus of xandarellid artiopodan known from the Cambrian of China, the type species Xandarella spectaculum was described in 1991 from the Cambrian Stage 3 aged Chengjiang Biota in China.{{cite journal |last1=Xianguang |first1=Hou |last2=Ramsköld |first2=Lars |last3=Bergström |first3=Jan |title=Composition and preservation of the Chengjiang fauna –a Lower Cambrian soft‐bodied biota |journal=Zoologica Scripta |date=October 1991 |volume=20 |issue=4 |pages=395–411 |doi=10.1111/j.1463-6409.1991.tb00303.x}} Although an additional species Xandarella mauretanica was described from the Cambrian Stage 5 Tatelt Formation in Morocco in 2017, which preserved only the ventral anatomy,{{Cite journal|last1=Ortega-Hernández|first1=Javier|last2=Azizi|first2=Abdelfattah|last3=Hearing|first3=Thomas W.|last4=Harvey|first4=Thomas H. P.|last5=Edgecombe|first5=Gregory D.|last6=Hafid|first6=Ahmid|last7=El Hariri|first7=Khadija|date=March 2017|title=A xandarellid artiopodan from Morocco – a middle Cambrian link between soft-bodied euarthropod communities in North Africa and South China|url= |journal=Scientific Reports|language=en|volume=7|issue=1|pages=42616|doi=10.1038/srep42616|issn=2045-2322|pmc=5314411|pmid=28211461|bibcode=2017NatSR...742616O}} it is later found that is a species of trilobite Gigoutella instead.{{Cite journal |last=El Albani |first=Abderrazak |last2=Mazurier |first2=Arnaud |last3=Edgecombe |first3=Gregory D. |last4=Azizi |first4=Abdelfattah |last5=El Bakhouch |first5=Asmaa |last6=Berks |first6=Harry O. |last7=Bouougri |first7=El Hafid |last8=Chraiki |first8=Ibtissam |last9=Donoghue |first9=Philip C. J. |last10=Fontaine |first10=Claude |last11=Gaines |first11=Robert R. |last12=Ghnahalla |first12=Mohamed |last13=Meunier |first13=Alain |last14=Trentesaux |first14=Alain |last15=Paterson |first15=John R. |date=2024-06-28 |title=Rapid volcanic ash entombment reveals the 3D anatomy of Cambrian trilobites |url=https://www.science.org/doi/10.1126/science.adl4540 |journal=Science |language=en |volume=384 |issue=6703 |pages=1429–1435 |doi=10.1126/science.adl4540 |issn=0036-8075}} Like other Xandarellids, the exoskeleton is unmineralised. The cephalon has pronounced eye slits, presumably derived from ancestral ventral stalked eyes.{{Cite journal|last1=Chen|first1=Xiaohan|last2=Ortega-Hernández|first2=Javier|last3=Wolfe|first3=Joanna M.|last4=Zhai|first4=Dayou|last5=Hou|first5=Xianguang|last6=Chen|first6=Ailin|last7=Mai|first7=Huijuan|last8=Liu|first8=Yu|date=December 2019|title=The appendicular morphology of Sinoburius lunaris and the evolution of the artiopodan clade Xandarellida (Euarthropoda, early Cambrian) from South China|url= |journal=BMC Evolutionary Biology|language=en|volume=19|issue=1|pages=165|doi=10.1186/s12862-019-1491-3|issn=1471-2148|pmc=6685191|pmid=31387545 |doi-access=free }}