Daidal

{{Short description|Extinct genus of mantis shrimp}} {{Automatic taxobox | fossil_range = {{Fossil range|Late Mississippian|Early Pennsylvanian}} | image = †Tyrannophontes acanthocercus Unt Karbon Bear Gulch Montana USA Ar886a.jpg | image_caption = Fossil of ''D. acanthocercus'' |parent_authority = Schram, 2007 | taxon = Daidal | authority= Schram, 2007 | type_species = {{extinct}}'''''Tyrannophontes acanthocercus''''' | type_species_authority = Jenner ''et al.'', 1998 | subdivision_ranks = Species | subdivision = *{{extinct}}'''''D. acanthocercus''''' Jenner ''et al.'', 1998 *{{extinct}}'''''D. pattoni''''' Peach, 1908 *{{extinct}}'''''D. schoellmanni''''' Schram, 2007 | synonyms = '''''D. acanthocercus''''' *''Tyrannophontes acanthocercus'' {{small|Jenner ''et al.'', 1998}} '''''D. pattoni''''' *''Perimecturus pattoni'' {{small|Peach, 1908}} *''Tyrannophontes pattoni'' {{small|Clark, 1989}} }}

'''''Daidal''''' (named after a spirit in Takelma mythology) is an extinct genus of mantis shrimp that lived during the Carboniferous period. It is the only genus in the family '''Daidalidae'''. Three species are currently placed within the genus. Fossils of the type species, '''''D. acanthocercus''''', have been found in the Bear Gulch Limestone of Montana. A second species, '''''D. pattoni''''', is known from the Lower Limestone Formation of Scotland, and the third species, '''''D. schoellmanni''''', was discovered in Westphalia, Germany. The genus has been proposed to be polyphyletic, with ''D. pattoni'' possibly being an earlier diverging lineage, though more specimens and research are needed to confirm this.

==Taxonomic history== thumb|Holotype of ''Daidal pattoni'' as illustrated in 1908, originally labelled as ''Perimecturus pattoni'' Fossilized remains of ''Daidal'' were first described almost a century before the genus was named. In 1908, Ben Peach studied several crustacean fossils from the Carboniferous deposits in Scotland, and erected the species ''Perimecturus pattoni'' based on a single specimen (G 1887.25.1059) collected from the Top Hosie Limestone of the Lower Limestone Formation near East Kilbride, believing it belonged in the genus ''Perimecturus''. The specific name honors Andrew Patton, manager of the Calderwood Cement Works, who collected this fossil.<ref name=":2">{{Cite book |last=Peach |first=B. N. |url=https://www.biodiversitylibrary.org/item/41415 |title=Monograph on the higher Crustacea of the Carboniferous rocks of Scotland |date=1908 |publisher=Printed for H.M. Stationery off., by J. Hedderwick & sons, ltd |location=Glasgow}}</ref> Clark (1989) would report on additional material of this species and move it into the genus ''Tyrannophontes'' as ''Tyrannophontes pattoni'', though Lothar Schöllman placed it back into ''Perimecturus'' in 2004.<ref>{{Cite thesis |title=A Study of a Namurian Crustacean-Bearing Shale From the Western Midland Valley of Scotland |url=https://theses.gla.ac.uk/77926/ |date=1989 |place=Ann Arbor |degree=PhD |language=en |first=Neil Donald Lewis |last=Clark}}</ref><ref name=":3">{{Cite journal |last=Schöllman |first=Lothar |date=2004 |title=Archaeostomatopodea (Malacostraca, Hoplocarida) aus dem Namur B (höheres Marsdenium, Karbon) von Hagen-Vorhalle (NRW, Deutschland) und eine Neudefinition einiger Arten der Familie Tyrannophontidae |journal=Geologie und Paläontologie in Westfalen |volume=62 |pages=111–141}}</ref>

Jenner ''et al.'' (1998) analysed numerous stomatopod specimens from the Bear Gulch Limestone. They recognized that some of these specimens, formerly thought to represent ''Bairdops beargulchensis'' or ''Tyrannophontes'' ''theridion'', represent a new species which they named ''Tyrannophontes acanthocercus''. The specimen CM 34453 was selected as the holotype of this species. The specific name is combined from the Greek ''akanthos'' (meaning "thorn") and ''kerkos'' (meaning "tail"), in reference to the spines on the telson.<ref name=":0">{{Cite journal |last1=Jenner |first1=Ronald A. |last2=Hof |first2=Cees H. J. |last3=Schram |first3=Frederick R. |date=1998 |title=Palaeo- and archaeostomatopods (Hoplocarida, Crustacea) from the Bear Gulch Limestone, Mississippian (Namurian), of central Montana |url=https://www.academia.edu/56829561 |journal=Contributions to Zoology |volume=67 |issue=3 |page=155 |doi=10.1163/18759866-06703001 |issn=1383-4517|doi-access=free }}</ref>

Lothar Schöllman studied the remains of another stomatopod species collected from Hagen-Vorhalle, Westphalia, Germany, and in 2004 he concluded they were mostly similar to ''Gorgonophontes'', assigning them to ''Gorgonophontes'' cf. ''fraiponti''.<ref name=":3" /> Other authors before him had tentatively assigned the specimens to ''Perimecturus'' or ''Tyrannophontes''.<ref>{{Cite journal |last1=Brauckmann |first1=Carsten |last2=Koch |first2=Lutz |date=1983 |title=''Prothelyphonus naufragus'' n. sp., ein neuer Geißelskorpion aus dem Namurium (unteres Ober-Karbon) von West- Deutschland |url=https://www.researchgate.net/publication/259867905 |journal=Entomologia Generalis |volume=9 |issue=1/2 |pages=63–73|doi=10.1127/entom.gen/9/1983/63 }}</ref><ref>{{Cite journal |last1=Brauckmann |first1=Carsten |last2=Koch |first2=Lutz |last3=Kemper |first3=Michael |date=January 1985 |title=Spinnentiere (Arachnida) und Insekten aus den Vorhalle-Schichten (Namurium B, Ober-Karbon) von Hagen-Vorhalle (West-Deutschland) |url=https://www.academia.edu/28823552 |journal=Geologie und Paläontologie in Westfalen |volume=3 |pages=1–132}}</ref>

In 2007, Frederick Schram conducted a study revising the classification of Paleozoic stomatopods. He found that the fossils assigned to ''Tyrannophontes acanthocercus'' differed significantly from the holotype of ''Tyrannophontes'', and that the species should be placed in a separate genus. The genus ''Daidal'' was thus erected, with ''T. acanthocercus'' (now renamed ''Daidal acanthocercus'') as the type species. The generic name references a spirit in Takelma mythology of the same name. Schram also found ''Perimecturus pattoni'' to be similar to ''D. acanthocercus'' in features of the pleon and telson, therefore reclassifying it as a second species of ''Daidal'' now named ''Daidal pattoni''. In addition, the German remains assigned to ''Gorgonophontes'' cf. ''fraiponti'' were also discovered by Schram to be similar to specimens of ''Daidal'', so the species ''Daidal schoellmanni'' was erected based on them. The specific name honors Lothar Schöllman for his earlier work on this species.<ref name=":1">{{Cite journal |last=Schram |first=Frederick R. |date=2007 |title=Paleozoic Proto-Mantis Shrimp Revisited |journal=Journal of Paleontology |volume=81 |issue=5 |pages=895–916 |doi=10.1666/pleo05-075.1 |jstor=4498847 |bibcode=2007JPal...81..895S |s2cid=85606671 |issn=0022-3360}}</ref>

==Description== ''Daidal'' is an invertebrate of moderate size, with the type species ''D. acanthocercus'' reaching a body length of {{convert|20|-|80|mm|abbr=on|in}}. Each antennule has three flagellae of around equal length. The mandibles are large and heavily sclerotised, located around three fifths the length of the carapace from the posterior edge of the carapace. The carapace is only slightly longer than it is tall, enveloping the front of the thorax (apart from its underside), with a subtriangular shape in side view and subrectangular shape in top view. The top of the carapace extends towards the front margin of the fifth thorax segment, while wing-like extensions on its sides extend to the front margins of the sixth thorax segment, and a furrow stretches along the carapace margins.<ref name=":0" /><ref name=":1" />

thumb|3D reconstruction of ''D. schoellmanni'' The second to fifth thorax segments each possess a pair of maxillipeds (appendages which function as mouthparts), which are similar in shape and size. These are enlarged and served as raptorial appendages for catching prey. The propodi (penultimate segment) of the maxillipeds are large and subrectangular, with two parallel rows of spines: a row of moveable large spines on the outer side and a row of small spines on the inner side. The dactyli (final segment) of the maxillipeds are thin and blade-like, curving towards the body.<ref name=":0" />

The pleon is around a third longer than the cephalothorax, with each segment being slightly larger than the one in front of it. The segments are non-overlapping and have rounded corners, with furrows and ridges on the margins. The pleopods are heavily sclerotized, with the terminal segment being greatly enlarged. In ''D. acanthocercus'' and ''D. schoellmanni'' the tergites are undecorated, whereas those of ''D. pattoni'' have rippled decoration. The segment of the uropod closest to the body has two backwards-pointing spines. Paired keels are present on the subrectangular and tapering telson, as are four movable spines on the margins of its underside.<ref name=":1" />

==Classification== The species now assigned to ''Daidal'' have been placed in various other genera in the past, and thus have also been positioned in different families. ''D. acanthocercus'' was initially described as a species of ''Tyrannophontes,'' while ''D. pattoni'' was first named as a species of ''Perimecturus'', and therefore were assigned to the families Tyrannophontidae and Perimecturidae respectively.<ref name=":2" /><ref name=":0" /> The specimens of ''D. schoellmanni'' were at one point associated with the genus ''Gorgonophontes'' and by extension the family Gorgonophontidae.<ref name=":3" /> Frederick Schram was the first to recognize these species as members of the genus he named ''Daidal'' in 2007, and erected the family Daidalidae for this genus. The family belongs to the suborder Archaeostomatopodea and is monotypic, with ''Daidal'' being the type and only genus.<ref name=":1" />

Smith ''et al.'' (2023) conducted a phylogenetic analysis to determine the relations between fossil mantis shrimps, which recovered the genus ''Daidal'' to be polyphyletic. While ''D. acanthocercus'' and ''D. schoellmanni'' were recovered as sister taxa, these two species were also recovered to be more closely related to ''Gorgonophontes'' than to the earlier-diverging ''D. pattoni''. However, it was noted that this result may be due to a lack of data on the thoracic appendages of ''D. pattoni''. The results of the analysis are displayed in the cladogram below:<ref>{{Cite journal |last1=Smith |first1=C.P.A. |last2=Aubier |first2=P. |last3=Charbonnier |first3=S. |last4=Laville |first4=T. |last5=Olivier |first5=N. |last6=Escarguel |first6=G. |last7=Jenks |first7=J.F. |last8=Bylund |first8=K.G. |last9=Fara |first9=E. |last10=Brayard |first10=A. |date=2023-03-31 |title=Closing a major gap in mantis shrimp evolution - first fossils of Stomatopoda from the Triassic |url=https://www.researchgate.net/publication/369959650 |journal=Bulletin of Geosciences |language=en |pages=95–110 |doi=10.3140/bull.geosci.1864 |issn=1802-8225|doi-access=free }}</ref>

==Palaeobiology== thumb|Restoration of ''D. acanthocercus'' Based on the diet of other mantis shrimps and the fact that it has enlarged raptorial appendages, ''Daidal'' is believed to have been a carnivore. In extant unipeltatan mantis shrimps, the raptorial appendages (the second pair of thoracopods) have a specialized joint associated with a set of muscles to form a click-joint mechanism, allowing the appendages to rapidly extend and capture prey.<ref>{{Cite journal |last=Kunze |first=Janet C. |date=1981 |title=The Functional Morphology of Stomatopod Crustacea |journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences |volume=292 |issue=1059 |pages=255–328 |doi=10.1098/rstb.1981.0032 |jstor=2395431 |bibcode=1981RSPTB.292..255K |issn=0080-4622}}</ref> However, ''Daidal'' probably lacked this mechanism, instead having raptorial appendages that more closely resemble the smaller, third to fifth thoracopods of unipeltatans used to manipulate prey after capture. It has thus been suggested by Jenner ''et al.'' (1998) that basal stomatopods like ''Daidal'' were opportunistic scavengers which primarily handled dead food.<ref name=":0" /> On the other hand, Haug & Haug (2021) theorized that early mantis shrimps were benthopelagic predators, swimming above the seabed while they hunted, possibly by grabbing their prey from above. This was supported by the appendage morphology in ''Tyrannosculda'', ''Tyrannophontes'' and ''Gorgonophontes'', showing these early forms could not attack prey from the seabed.<ref>{{Cite journal |last1=Haug |first1=Carolin |last2=Haug |first2=Joachim T. |date=2021-04-16 |title=A new fossil mantis shrimp and the convergent evolution of a lobster-like morphotype |journal=PeerJ |language=en |volume=9 |article-number=e11124 |doi=10.7717/peerj.11124 |issn=2167-8359 |pmc=8054755 |pmid=33959413 |doi-access=free }}</ref> This method of hunting is also observed in the larvae of extant mantis shrimps, and studying them may help increase our understanding of early stomatopod ecology.<ref>{{Cite journal |last=Pyne |first=Rex R. |date=1972 |title=Larval development and behaviour of the mantis shrimp, Squilla armata Milne Edwards (Crustacea: Stomatopoda) |journal=Journal of the Royal Society of New Zealand |language=en |volume=2 |issue=2 |pages=121–146 |doi=10.1080/03036758.1972.10429369 |bibcode=1972JRSNZ...2..121P |issn=0303-6758|doi-access=free }}</ref><ref>{{Cite journal |last1=Haug |first1=Joachim T. |last2=Haug |first2=Carolin |last3=Maas |first3=Andreas |last4=Kutschera |first4=Verena |last5=Waloszek |first5=Dieter |date=2010-09-21 |title=Evolution of mantis shrimps (Stomatopoda, Malacostraca) in the light of new Mesozoic fossils |journal=BMC Evolutionary Biology |volume=10 |issue=1 |page=290 |doi=10.1186/1471-2148-10-290 |issn=1471-2148 |pmc=2955030 |pmid=20858249 |bibcode=2010BMCEE..10..290H |doi-access=free }}</ref>

==References== {{Commons category|position=left|Daidal}} {{Wikispecies|position=left|Daidal}} {{Reflist}}

Category:Carboniferous animals of North America Category:Carboniferous arthropods of Europe Category:Stomatopoda Category:Fossil taxa described in 2007 Category:Prehistoric crustacean genera Category:Prehistoric mantis shrimps