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Early Jurassic Polychelida with preserved compound eye structures. a-d. Gabaleryon sp. specimen SMNS 67631 from the Toarcian of Gomaringen. e-h. Coleia viallii, holotype MSNM i3368 from the Sinemurian of Osteno. i-j. Coleia barrovensis, specimen NHMUK.I6589 (photo © NHMUK) from the Hettangian of Binton. a, e, i. Overview of presumed compound eye structures. b-c, f-g. Details of square facets, note that each square facet is surrounded by eight neighbor facets, see asterisks (*) in c (same image as b) and g (same image as f). d, h, j. Overview of entire specimens
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Background:
Modern representatives of Polychelida (Polychelidae) are considered to be entirely blind and have largely reduced eyes, possibly as an adaptation to deep-sea environments. Fossil species of Polychelida, however, appear to have well-developed compound eyes preserved as anterior bulges with distinct sculpturation.
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... This includes re-description of the specimen of Palaeopolycheles longipes previously shown in Schweigert & Dietl [42]. We also illustrate new specimens of Mesozoic Polychelida from Solnhofen-type plattenkalks (Late Jurassic; Figs. 1 and 2), La Voulte-sur-Rhône (Middle Jurassic: Figs. 3, 4 and 5), and Gomaringen, Osteno and Binton (Early Jurassic: Fig. 6) and compare them to other fossil arthropods, whose living relatives possess well-developed eyes (Figs. 7 and 8). Based on these observations, we discuss the evolution of eye types and optical mechanisms within Polychelida and propose new ideas on the visual ecology of fossil ...
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Achelatan lobsters, also known as spiny and slipper lobsters, develop via a highly specialised larval form. This special larva, phyllosoma, is flat, translucent, possesses elongate legs and can grow to enormous sizes. Although these larvae may appear very fragile, they are well-known as fossils. Thousands of specimens have been found in the lithogr...
Citations
... 3K. Audo et al., 2016: Eryon calvadosi Woodward, 1911: 307. Balss, 1924: 175. ...
Polychelidan lobsters are decapod crustaceans characterized by their four to five pairs of claws. The first description of a polychelidan lobster dates back to 1817, and since then, numerous species have been described with varying level of details. This situation sometimes led to the description of synonymous species, and more generally, led to a lack of overview on the group systematic and evolutionary history. Herein, we review Proeryon¸ one of the most diversified and stratigraphically widespread polychelidan. We argue that Proeryon is closely allied to Tethyseryon and Gabaleryon and propose to assign them to Proeryoninae nov. subfam., which are mainly characterized by their hemicircular ocular incision, postorbital and branchial carinae not joined together, and axial carina on pleonites cut by transverse grooves. Proeryon is in turn characterized by its marked cervical and hepatic incisions, simple posterolateral spines and arched uropodal exopod diaeresis. Thus defined, we assign the following species to Proeryon: P. charbonnieri, P. giganteus, P. hauffi, P. laticaudatus, P. richardsoni, P. stoddarti and two unnamed species from the Hauterivian of Germany and Switzerland, respectively. In addition, we refer to Proeryon, with some reservations, two new species,?Proeryon quiltyi from the Callovian of Antarctica and?Proeryon erinaceus from the Oxfordian of France. Proeryon has highly discontinuous but large stratigraphic (Pliensbachian – Hauterivian: about 60 MA) and palaeogeographic (from United Kingdom to Siberia, and to Antarctica) distribution. Most of these species occurs in relatively deep neritic or deeper palaeoenvironments. It is possible that this deep-sea dwelling is one of the reasons why Proeryon survived so long. Also, we note the presence of abundant oysters living as epibionts on some specimens of Proeryon hartmanni. Their disposition and number suggest that P. hartmanni was an epibenthic animal.
... The large, circular structures at the anterior end of the body are interpreted as eyes. Crayfish eyes are prominent structures, and can be well preserved (Audo et al., 2016). They are positioned rather more posteriorly in relation to the appendages than in living crayfish examined, but that may be the morphology of the fossil species. ...
A supposed giant spider, Mongolarachne chaoyangensis Cheng, Liu, Huang, Liu, Li & Li, 2019, from the Lower Cretaceous Yixian Formation of China, is here shown, with the aid of fluorescence microscopy, to be a faked fossil spider, with a fossil crayfish as its core. We tentatively place M. chaoyangensis in Cricoidoscelosus aethus Taylor, Schram & Shen, 1999 n. syn..
... Noticeably, a number of decapod lineages have independently retained the larval apposition eyes 20,26 , or have evolved refractive or parabolic superposition eyes while retaining a hexagonal packing 27 . Previously, Rogeryon oppeli (Woodward, 1866) was the only polychelidan considered to have hexagonal facets (most likely apposition eyes) retained due to paedomorphic, more precisely neotenic evolution 5 . Voulteryon parvulus is probably also a paedomorphic form 28 , so it is more parsimonious to consider that its hexagonally-packed ommatidia correspond to larval apposition optics retained in adulthood as in R. oppeli. ...
... It is also possible, yet probably less parsimonious, that V. parvulus, and perhaps also Rogeryon oppeli 5 , had a type of superposition optics that did not require square facets: refractive or parabolic superposition optics. From the fossil alone we cannot distinguish between these two options. ...
... These 'mirror' eyes are well suited for dim-light conditions, and are commonly seen across nocturnal or deep-water decapod taxa 31 . . Original data for V. parvulus from the present study; for polychelidans, from Audo et al. 5 ; for phyllosoma, from Tanaka et al. 34 ; for Dollocaris ingens, from Vannier et al. 10 . ...
Exceptional and extremely rare preservation of soft parts, eyes, or syn-vivo associations provide crucial palaeoecological information on fossil-rich deposits. Here we present exceptionally preserved specimens of the polychelidan lobster Voulteryon parvulus, from the Jurassic of La Voulte-sur-Rhône Fossil-Lagerstätte, France, bearing eyes with hexagonal and square facets, ovaries, and a unique association with epibiont thecideoid brachiopods, giving insights onto the palaeoenvironment of this Lagerstätte. The eyes, mostly covered in hexagonal facets are interpreted as either apposition eyes (poorly adapted to low-light environment) or, less likely, as refractive or parabolic superposition eyes (compatible with dysphotic palaeoenvironments). The interpretation that V. parvulus had apposition eyes suggests an allochthonous, shallow water origin. However, the presence of thecideoid brachiopod ectosymbionts on its carapace, usually associated to dim-light paleoenvironments and/or rock crevices, suggests that V. parvulus lived in a dim-light setting. This would support the less parsimonious interpretation that V. parvulus had superposition eyes. If we accept the hypothesis that V. parvulus had apposition eyes, since the La Voulte palaeoenvironment is considered deep water and had a soft substrate, V. parvulus could have moved into the La Voulte Lagerstätte setting. If this is the case, La Voulte biota would record a combination of multiple palaeoenvironments.
... The occurrence of Tetrachela raiblana in a deep-water palaeoenvironment is important in the broader context of polychelidan evolutionary history. Indeed, T. raiblana is one of the earliest polychelidans and several younger fossil species, for instance Tethyseryon campanicus Bravi, Garassino, Bartiromo, Audo, Charbonnier, Schweigert, Thévenard and Longobardi, 2014 and all species from Solnhofen-type outcrops were recorded from shallow water palaeoenvironments (Ahyong, 2009;Audo et al., 2014aAudo et al., , 2014bAudo et al., , 2016. However, T. raiblana shows well-developed ocular incisions which suggest the presence of developed and functional eyes. ...
Polychelidan lobsters, as the sister group of Eureptantia (other lobsters and crabs), have a key-position within decapod crustaceans. Their evolutionary history is still poorly understood, although it has been proposed that their Mesozoic representatives largely inhabited shallow-marine environment and only later sought refuge in deep water. This view has recently been challenged, so the evolutionary history of polychelidans is in a need of re-appraisal. The earliest representatives, such as Tetrachela from the Late Triassic of Austria and Italy, are of great importance because of their potential in investigation of life habits of early polychelidans. Tetrachela lived in a relatively deep water, however, its well-developed eyes suggest an environment where light was still present. With its massive dorsoventrally flattened body plan, Tetrachela was probably benthic; the shape of its mandible and stocky first pereiopods suggest it was a scavenger and/or fed on slowly moving or sedentary animals. The carapace of Tetrachela has a peculiar groove pattern, which leads us to redefine some elements of the nomenclature of grooves used for polychelidans. Based on the present revision we propose that the second incision and its associated groove correspond to the hepatic groove, not the postcervical or the branchiocardiac grooves as interpreted previously. This revision allows us to review the homologies of cephalothoracic groove between polychelidans and other notable groups of decapod crustaceans.
... (2) an ovoid, almost pear-shaped exoskeleton wider in its anterior half, distinct from other polychelidans (clearly ovoid, subcircular or pear-shaped, larger in posterior half in almost all other species); (3) a rounded telson, as in Rosenfeldia, rare in polychelidans (generally triangular); (4) a first pereiopod about as large as succeeding ones, generally larger in other polychelidans, except in the poorly preserved Wrangelleryon perrates Feldmann, Schweitzer & Haggart, 2013; (5) finally, as indicated by Audo et al. (2016), Eryon oppeli possesses hexagonal ommatidia, contrary to all other polychelidans, for which preserved quadratic ommatidia were documented. Considering only these points, E. oppeli could resemble W. perrates, but these two species do not seem to be closely related as they differ in many aspects: W. perrates is narrower, has European Journal of Taxonomy 367: 1-23 (2017) petaloid uropodal endopod and exopod, and its P5 is larger in proportion. ...
... (1) a very thin, probably soft, carapace, (2) eyes with hexagonal ommatidia (probably apposition eyes: Audo et al. 2016), (3) P1 almost as large as P2-P4. Since none of these traits are common among polychelidan lobsters, most of them are likely autapomorphies (unique to Rogeryon oppeli) and unlikely to be ancestral characters retained in Rogeryon oppeli, but lost in most or all other polychelidans. ...
... This character seems congruent with the shallow water palaeoenvironments attributed to the Solnhofen-type outcrops. However, it should be noted that other polychelidans from Solnhofen-type outcrops with preserved ommatidia, had reflection superposition eyes (quadrate ommatidia: Audo et al. 2016). Therefore, the palaeoenvironment alone cannot explain the eye-type of R. oppeli. ...
Polychelidan lobsters (Decapoda: Polychelida) are crustaceans with extant species which are restricted to deep water environments. Fossil species, however, used to live in more varied palaeoenvironments, from shallow water to deep water, and were more diverse morphologically. We redescribe two species of polychelidan lobsters, the Late Triassic Rosenfeldia triasica Garassino, Teruzzi & Dalla Vecchia, 1996 and the Late Jurassic Eryon oppeli Woodward, 1866, recently assigned to the same genus, Rosenfeldia, based upon only a few characters. Our investigation of all available material of both species leads us to distinguish these two species and to erect Rogeryon gen. nov. to accommodate Eryon oppeli. The palaeobiology of both species is interpreted for the first time. Rosenfeldia triasica with its stout first pereiopods and mandibles with both incisor and molar processes (documented for the first time in Polychelida) was benthic and probably fed either on slow-moving sedentary preys or was a scavenger. Rogeryon oppeli gen. et comb. nov. was benthic, visually adapted to shallow water palaeoenvironments, and possibly had a diet similar to that of slipper lobsters and horseshoe crabs. The redescription of these two species highlights the palaeobiological diversity of fossil polychelidans.
... The more recent Antarcticheles antarcticus (Kimmeridgian-Tithonian) also closely resembles modern polychelids, but surprisingly had rather large ocular incisions, which suggests that it possessed an eye with a developed visual surface. The visual surface is always reduced in extant species (Galil 2000), but is often developed in fossil species (Spence Bate 1888; Schweigert & Dietl 1999;Audo et al. 2014bAudo et al. , c, 2016Audo 2016). Finally, Haug et al. (2015) described, in the Late Cretaceous of Lebanon, crustaceans they interpreted as polychelidan larvae bearing eyes with a well-preserved visual surface. ...
Polychelidan lobsters are one of the rare groups of decapod crustaceans which were first discovered as fossils long before being identified in extant deep-sea environments. As for other decapods, their fossil record is highly incomplete, which complicates the reconstruction of their evolutionary history. Another problem that hinders better knowledge of the group is familial assignments, which can be difficult in the absence of a complete revision of known fossil taxa. As a result, only three fossil Polychelidae have been identified to date, the oldest dating back to the Callovian (Middle Jurassic). In the present study, we consider two rarely studied species, Palaeopolycheles crymensis Levitski, 1974 from the Toarcian–Aalenian (Early–Middle Jurassic) of Crimea (Ukraine), and Eryon neocomiensis Woodward, 1881 from the Valanginian (Early Cretaceous) of the Outer Carpathians (Czech Republic). Our reinvestigations indicate they present several characters typical of Polychelidae, and are actually morphologically quite similar to extant species, notably in the structure of the anterior part of the carapace and the small ocular incisions. Two new genera are erected to accommodate them: Tauricheles gen. nov. (type species Palaeopolycheles crymensis) and Woodwardicheles gen. nov. (type species Eryon neocomiensis). The reinvestigations show that: (1) the evolutionary history of Polychelidae is much older than previously considered; (2) Polychelidae have inhabited deep water for a long time; (3) both species are probably autochthonous or parautochthonous to turbiditic palaeoenvironments; (4) Woodwardicheles neocomiensis comb. nov. is one of the rare benthic macrofossils of the Silesian Basin.
http://zoobank.org/urn:lsid:zoobank.org:pub:CE6FEEA7-4162-4AE2-9413-11FD38FE04B9
Laser-stimulated fluorescence (LSF) has seen increased use in palaeontological investigations in recent years. The method uses the high flux of laser light of visible wavelengths to reveal details sometimes missed by traditional long-wave ultraviolet (UV) methods using a lamp. In this study, we compare the results of LSF with UV-A-generated fluorescence on a range of fossils from the Upper Jurassic Solnhofen Limestone Konservat-Lagerstätte of Bavaria, Germany. The methodology follows previous protocols of LSF with modifications made to enhance laser beam intensity, namely keeping the laser at a constant distance from the specimen, using a camera track. Our experiments show that along with making surface details more vivid than UV-A or revealing them for the first time, LSF has the additional value of revealing shallow subsurface specimen detail. Fossil decapods from the Solnhofen Limestone reveal full body outlines, even under the matrix, along with details of segmentation within the appendages such as limbs and antennae. The results indicate that LSF can be used on invertebrate fossils along with vertebrates and may often surpass the information provided by traditional UV methods.
Polychelidan lobsters are unique decapod crustaceans characterized by having four or five pairs of claws. We still do not have a clear overview of the 69 described species of fossil polychelidans and, until now, little was known of their phylogenetic relationships. Our phylogenetic analysis includes 35 fossil polychelidans and offers the first high-resolution study of their relationships, uniting fossil and extant polychelidans. It shows that polychelidans are divided into five main lineages – two monospecific (Palaeopentacheles roettenbacheri and Rogeryon oppeli) and three clades (Eryonidae, Coleiidae and Polychelidae). The recent inclusion of Tetrachelidae within Coleiidae is confirmed. The analysis allowed the identification of diagnostic characters for Eryonidae and demonstrates that Eryon siburicus from the Toarcian is the oldest occurrence of this family. The diverse Coleia is polyphyletic. We were able to identify several trends in polychelidan evolution: (1) diversification of the main lineages probably predates the Late Triassic; (2) Eryonidae probably evolved fossorial adaptations independently; (3) the general trend to live in deeper water disappears when accounting for the bathyal distribution of each monophyletic group across time; (4) several lineages conquered shallow-water palaeoenvironments; and (5) fossil polychelids inhabited deep water as early as the Early–Middle Jurassic. Extant polychelidans are not refugees that adapted to deep water, but survivors of a group that was once more diverse both morphologically and ecologically.
http://zoobank.org/urn:lsid:zoobank.org:pub:A0E01F06-083B-426F-A5C3-6D6A8218A1A8
Polychelidan lobsters are a group of decapod crustaceans which, in terms of both numbers of species and morphology, were more diverse during the Triassic and Jurassic than their modern representatives (Polychelidae). Here a new genus and species from the Lower Jurassic of Switzerland, Angusteryon oberlii , is described. The new taxon is characterised by a particularly narrow cephalohoracic shield, which is an unusual trait in comparison to all other polychelidan lobsters, both fossil and extant. It is tentatively assigned to the Coleiidae here. A. oberlii nov. gen., nov. sp. was recovered from hemipelagic sedimentary rocks, suggesting that it inhabited a deep-water setting. Although there is a possibility that the present specimens could be parautochthonous, the small size of the ocular incisions may indicate that A. oberlii nov. gen., nov. sp. had either reduced vision or was blind, which could be explained by its having inhabited a deep-water habitat. If our views on this mode of life and taxonomic assignment are correct, this would suggest convergent degeneration of vision between the new taxon and the Polychelidae. Furthermore, features of the newly collected specimen augment the apparent morphological diversity displayed by polychelidan lobsters early in their history, as well as document a more substantial decrease of such since the Triassic and Jurassic than previously recorded.
