''Sartilmania'' is a

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 extinct

vascular plant Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Ti ...

s of the

Early Devonian The Early Devonian is the first of three Epoch (geology), epochs comprising the Devonian period, corresponding to the Lower Devonian Series (stratigraphy), series. It lasted from and began with the Lochkovian Stage , which was followed by the Pr ...

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

University of Liège The University of Liège (), or ULiège, is a major public university of the French Community of Belgium founded in 1817 and based in Liège, Wallonia, Belgium. Its official language is French (language), French. History The university was foun ...

, Belgium (after which the genus was named).

Description

The

sporophyte A sporophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the biological life cycle, life cycles of plants and algae. It is a diploid multicellular organism which produces asexual Spo ...

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 ''Stockmansella'' is a genus of extinct plants of the Middle Devonian (Eifelian stage, around ), fossils of which have been found in north-west Germany. The Alternation of generations, sporophyte generation consists of prostrate dichotomizing st ...

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 A sporangium (from Late Latin, ; : sporangia) is an enclosure in which spores are formed. It can be composed of a unicellular organism, single cell or can be multicellular organism, multicellular. Virtually all plants, fungus, fungi, and many ot ...

, 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 In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart a ...

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 se ...

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, ; : sporangia) is an enclosure in which spores are formed. It can be composed of a unicellular organism, single cell or can be multicellular organism, multicellular. Virtually all plants, fungus, fungi, and many ot ...

(spore-forming organs) were inconsistent with the definition of the

form genus Form classification is the classification of organisms based on their morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncertainty; the goal of sc ...

''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 language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

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 group of vascular plants that include the clubmosses. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineage ...

(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 Taxonomic rank#Ranks in botany, rank used for this group, ...

References

External links

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