Marginix
Genus of fossil echinoderms
Marginix is an extinct genus of brittle star in the family Encrinasteridae that lived during the Devonian period in South America and Africa. It contains three named species. The type species, M. yachalensis, was originally named as a species of Encrinaster in 1916, and its remains are known from Argentina. A second species, M. hilleri, was first described in 1999 based on specimens from South Africa, and a third species, M. notatus, originates from Brazil and was named in 2020. Fossils of Marginix were first recognized to represent a distinct genus in 1995, but the genus was only given its current name in 2015. Prior to this, it was given the names Marginaster and Marginura, but both were preoccupied and had to be replaced.
Discovery and naming
In 1916, a study by Rudolf Ruedemann describing some fossil material sent from Cerro Blanco, Jachal, Argentina to John Mason Clarke at the New York State Museum was published. The fossils, then thought to represent starfish remains, were recognized by Ruedemann to represent two new species, one of which he thought was a member of the genus Encrinaster and named Encrinaster yachalensis, the specific name referring to Jachal. Ruedemann studied a single specimen of this species, exhibiting the abactinal side of the animal, cataloged as NYSM 7762 and designated as the holotype of the species. Later in 1995, Reimund Haude discovered that this species, now known to be a brittle star, differs significantly from other species of Encrinaster, and thus transferred it to a new genus which he named Marginaster.
This brief starts where responsible research should: with the source description of “Marginix” as genus of fossil echinoderms. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the science & nature register because the source frames it as genus of fossil echinoderms. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Sep 29, 2025. The linked authority identifier is Q108460081. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1916, 1999, 2020 and 1995.
Current terminology should not be projected backward without checking the classification used when the underlying evidence was created. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Marginix”, its source revision and the description used here.
- Expand the search: follow Marginix primary sources, Marginix archive and Marginix research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Marginix”?
- Is the terminology current, historical or disputed?
- Which observation, specimen, dataset or publication supports the account?
Search terms from this dossier
This entry incorporates text from “Marginix” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.