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''Schinderhannes bartelsi'' is a
fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
species of hurdiid
radiodont Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and were used for a variety ...
(anomalocaridid), known from a single specimen from the Lower Devonian Hunsrück Slate in Germany. Its discovery expanded the known range of radiodonts, the latest members of which were previously known only from the
Early Ordovician The Early Ordovician is the first epoch (geology), epoch of the Ordovician period, corresponding to the Lower Ordovician series (stratigraphy), series of the Ordovician system. It began after the Cambrian Stage 10, Age 10 of the Furongian epoch o ...
, at least 66 million years earlier than ''Schinderhannes bartelsi''.


Discovery

The single specimen was discovered in the Eschenbach-Bocksberg Quarry in Bundenbach,
Rhineland-Palatinate Rhineland-Palatinate ( , ; ; ; ) is a western state of Germany. It covers and has about 4.05 million residents. It is the ninth largest and sixth most populous of the sixteen states. Mainz is the capital and largest city. Other cities are ...
, Germany, and is named after the outlaw Schinderhannes who frequented the area. Its
specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
''bartelsi'' honours Christoph Bartels, a Hunsrück Slate expert. The specimen is now housed in the
Naturhistorisches Museum The Natural History Museum Vienna () is a large natural history museum located in Vienna, Austria. The NHM Vienna is one of the largest museums and non-university research institutions in Austria and an important center of excellence for all matt ...
in
Mainz Mainz (; #Names and etymology, see below) is the capital and largest city of the German state of Rhineland-Palatinate, and with around 223,000 inhabitants, it is List of cities in Germany by population, Germany's 35th-largest city. It lies in ...
.


Morphology

''Schinderhannes'' is about long in full body length ( long excluding telsonDryad Data
). Like other
radiodonts Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and were used for a variety ...
, the head bears a pair of spiny frontal appendages, a radially-arranged ventral mouthpart ( oral cone), and a pair of large lateral compound eyes. Detailed morphology of the frontal appendages and oral cone are equivocal due to the limited preservation, but the former represent typical hurdiid features (e.g. subequal blade-like endites). The eyes were in a relatively anterior (forward) position in contrast to other hurdiids. There are traces of lateral structures originally thought to be the shaft regions of frontal appendages, which may rather represent P-elements (lateral
sclerites A sclerite (Greek , ', meaning " hard") is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly ...
) as seen in other radiodonts. The boundary of head and trunk ('neck') was broad with a pair of long, ventrally-protruded flaps. The trunk compose of 12 body segments indicated by soft dorsal
cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
(originally thought to be rigid tergites). The first 10 segments possess pairs of striated structures originally interpreted as biramous (branched) ventral flaps, but later investigations from other radiodonts (e.g. '' Lyrarapax'') suggest it may rather represent setal blades (dorsal gill-like structures of radiodont) and flap
muscles Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
. The 11th segment bears another pair of shorter, rounded flaps. The final segment lacking appendages and terminated with a long, spine-like
telson The telson () is the hindmost division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment (biology), segment of the arthropod body, or an additional division that is not a true segm ...
. A ventral
anus In mammals, invertebrates and most fish, the anus (: anuses or ani; from Latin, 'ring' or 'circle') is the external body orifice at the ''exit'' end of the digestive tract (bowel), i.e. the opposite end from the mouth. Its function is to facil ...
located immediately before the telson.


Ecology

The preserved contents of its digestive tract are similar to those of other predatory arthropods, and this lifestyle is supported by the raptorial nature of the spiny frontal appendages and the size of the eyes. ''Schinderhannes'' may have been an active swimmer (
nekton Nekton or necton (from the ) is any aquatic organism that can actively and persistently propel itself through a water column (i.e. swimming) without touching the bottom. Nektons generally have powerful tails and appendages (e.g. fins, pleopods, ...
), propelling itself with the long flaps attached to its head, and using its shorter flaps on the 11th segment to steer. These flaps presumably derived from the lateral flaps of Cambrian radiodonts that used lobes along their sides to swim, but lacked the specializations as seen in ''Schinderhannes''.


Classification

As a possible
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 ...
radiodont Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and were used for a variety ...
, the discovery of ''Schinderhannes'' was significant for extending the known range of the group, since the latest definitive radiodonts were only known from the
Early Ordovician The Early Ordovician is the first epoch (geology), epoch of the Ordovician period, corresponding to the Lower Ordovician series (stratigraphy), series of the Ordovician system. It began after the Cambrian Stage 10, Age 10 of the Furongian epoch o ...
, at least 66 million years before. This underlined the utility of
lagerstätte A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserv ...
n like the Hunsrück Slate, as the exceptionally preserved fossil horizons may be the only available opportunity to observe non-mineralised forms. The discovery of ''Schinderhannes'' has also prompted novel hypothesis about the classification of basal
arthropods Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
. One classification scheme has ''Schinderhannes''
sister A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...
to the euarthropods (
crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, parti ...
or 'true' arthropods) instead of other radiodonts, based on the characters which interpreted to be euarthropod-like (e.g. sclerotized
tergite A ''tergum'' (Latin for "the back"; : ''terga'', associated adjective tergal) is the Anatomical terms of location#Dorsal and ventral, dorsal ('upper') portion of an arthropod segment other than the head. The Anatomical terms of location#Anterior ...
, biramous appendage). This would mean that the euarthropod lineage evolved from a
paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...
grade of radiodonts, and that the group of basal arthropods with ' great/frontal appendages' are not a natural grouping, and the biramous appendages of arthropods may then have arisen through fusion of radiodont lateral flaps and gills. However, this scenario had been challenged by later investigations, as the putative euarthropod-like features were questioned to be rather radiodont-like characters (e.g. soft trunk
cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
, setal blades and paired flap muscles).
Phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...
analysis with focus on
Radiodonta Radiodonta is an extinct Order (biology), order of stem-group arthropods that was successful worldwide during the Cambrian period. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and were u ...
also repeatedly placed ''Schinderhannes'' within the radiodont family
Hurdiidae Hurdiidae (synonymous with the previously named Peytoiidae) is an extinct cosmopolitan distribution, cosmopolitan Family (biology), family of radiodonts, a group of Crown group#Stem groups, stem-group marine arthropods, which lived during the Pal ...
. Some researchers have remained skeptical of its taxonomic identity, questioning whether it is a hurdiid. In 2021, Zhu and colleagues argued that while the frontal appendages resemble those of radiodonts, the trunk anatomy of ''Schinderhannes'' is significantly different from the typical radiodont body plan, indicating that the hurdiid assignment should remain questionable before intermediate forms were discovered. In 2023, Potin and Daley considered its placement within Hurdiidae doubtful due to the huge gap in time between the latest definitive radiodonts from the
Early Ordovician The Early Ordovician is the first epoch (geology), epoch of the Ordovician period, corresponding to the Lower Ordovician series (stratigraphy), series of the Ordovician system. It began after the Cambrian Stage 10, Age 10 of the Furongian epoch o ...
.


References


External links


Origin of claws seen in 390-million-year-old fossil



ScienceBlogs: ''Schinderhannes bartelsi'', by PZ Myers
showing 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 ...
as proposed by G. Kühl et al., placing ''Schinderhannes'' (but not ''Anomalocaris'') into the group of Euarthropoda. {{Good article Devonian animals of Europe Radiodonta Fossils of Germany Fossil taxa described in 2009 Hunsrück Slate fossils