''Sartilmania'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of extinct

vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They ...

s of the

Early Devonian The Early Devonian is the first of three epochs comprising the Devonian period, corresponding to the Lower Devonian series. It lasted from and began with the Lochkovian Stage , which was followed by the Pragian from and then by the Emsian, ...

(Emsian stage, around ). Fossils were found on the Sart Tilman campus of the

University of Liège The University of Liège (french: Université de Liège), or ULiège, is a major public university of the French Community of Belgium based in Liège, Wallonia, Belgium. Its official language is French. As of 2020, ULiège is ranked in the 301 ...

, Belgium (after which the genus was named).

Description

The sporophyte of ''Sartilmania jabachensis'' has narrow leafless stems (axes), from 0.75 mm to a maximum of 2 mm in diameter, marked with irregular longitudinal striations, which allows them to be distinguished from the stems of '' Stockmansella langii'', with which they are mixed in the deposit. The plant is heavily and irregularly branched, with the lateral branches being arranged spirally. Each lateral branch appears to have ended in a vertically oriented sporangium, which caused a sharp upwards turn if the branch it terminated was near to the horizontal. The sporangia were spatulate (spoon-shaped), most measuring 3.5–4 mm long by 2.5-3.5 mm wide, marked by the same longitudinal striations as were present on the stems. The sporangia opened into two valves along their distal margins. Spores were not found; nor was the

vascular system The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

of the stems observed. The

gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the ...

is not known.

Taxonomy

Fairon-Demaret investigated fossils from Sart-Tilman (Liège, Belgium), and discovered that some specimens were identical to those previously called ''Dawsonites jabachensis''. However details of the shape of the

sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cyc ...

(spore-forming organs) were inconsistent with the definition of the form genus ''Dawsonites'', so Fairon-Demaret transferred the species to a new genus, ''Sartilmania''.

Phylogeny

''Sartilmania'' has similarities with the genus '' Renalia''. However, the way in which the sporangia of ''Sartilmania'' turn upwards and their spatulate rather than reniform (kidney-like) shape distinguish the two genera. In 2004, Crane et al. published a

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

for the

polysporangiophyte Polysporangiophytes, also called polysporangiates or formally Polysporangiophyta, are plants in which the spore-bearing generation (sporophyte) has branching stems (axes) that bear sporangia. The name literally means 'many sporangia plant'. The cl ...

s, in which ''Sartilmania'', like ''Renalia'', is placed basal to the

lycophytes The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldes ...

(clubmosses and relatives). Hao and Xue in 2013 listed the genus as a

rhyniophyte The rhyniophytes are a group of extinct early vascular plants that are considered to be similar to the genus '' Rhynia'', found in the Early Devonian (around ). Sources vary in the name and rank used for this group, some treating it as the class ...

References

External links

Cladogram
from {{Taxonbar, from=Q7424672 Early Devonian plants Prehistoric plant genera