Palaeontinidae

Palaeontinidae Temporal range: Rhaetian to Early Aptian PreЄ Є O S D C P T J K Pg N
Prolystra lithographica
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hemiptera
Suborder:	Auchenorrhyncha
Infraorder:	Cicadomorpha
Superfamily:	†Palaeontinoidea
Family:	†Palaeontinidae Handlirsch, 1906
Type genus
†Palaeontina Butler , 1873
Genera
See text
Synonyms
†Cicadomorphidae Evans, 1956

Palaeontinidae, commonly known as giant cicadas, is an extinct family of cicadomorphs. They existed during the Mesozoic era of Europe, Asia, and South America. The family contains around 30 to 40 genera and around a hundred species.

Discovery

The first palaeontinid discovered was Palaeontina oolitica. It consisted of a single forewing collected from the Taynton Limestone Formation (Stonesfield Slate) of Oxfordshire, England by the English natural historian Edward Charlesworth. It was first described in 1873 by the English entomologist Arthur Gardiner Butler in his book Lepidoptera Exotica; or, Descriptions and Illustrations of Exotic Lepidoptera. Butler claimed that it was the oldest butterfly ever recovered, having mistakenly identified it as a butterfly of the family Nymphalidae.

Description and paleobiology

Palaeontinids had large bodies covered with bristles (setae). They had small heads and broad wings. They superficially resemble moths. Large palaeontinids like Colossocossus had forewings that reached the length of 57 to 71 mm (2.2 to 2.8 in). They possessed an inflated frons and a long rostrum (piercing and sucking mouthpart), indicating that they fed on xylem fluids like some other modern hemipterans.

The host plants of palaeontinids have been assumed to be ginkgophytes based on the geographic distribution of both groups. The extinction of palaeontinids during Early Cretaceous has been linked to the decline of ginkgophytes at the end of the Mesophytic era (Late Permian to Middle Cretaceous) and the rise of angiosperms (flowering plants). Numerous newly evolved insectivorous animals (feathered theropods, primitive mammals, and early birds) may have also contributed significantly to their extinction.

Most species of palaeontinids exhibit cryptic coloration. The patterns on their wings protected them as they perched on branches and fed on sap. They may also have served as secondary sexual characteristics. The color patterns can vary slightly within the same species.

Palaeontinids, like modern cicadas, possess four membranous wings supported by veins. The length and width ratio of the wings can vary within the same species, sometimes as a result of fossil preservation. Early Jurassic palaeontinids, like Suljuktocossus, exhibit the most primitive wing forms in the family. The forewing was elliptical with the "nodal line" (the area where the wing bends during flight, also known as the "transverse flexion line") more or less dissecting through the center of the wing. The hind wing was short and broad. The bases of the forewings overlapped that of the hind wings like in modern butterflies. Taken together with their large bodies, these characteristics indicate that they were fast but moderately versatile fliers.

In contrast, later palaeontinids like the Upper Jurassic Eocicada and Early Cretaceous Ilerdocossus had triangular forewings with the flexion line closer to the base. They had smaller and narrower hind wings that did not overlap with the forewing. These indicate that they were highly versatile fliers, able to fly with a wide range of speeds and agility like modern wasps and sphinx moths. They also possessed changes to the leading edge of their forewings, suggesting an overall gain in lift.

The trend of forewing elongation is most evident in members of the family Mesogereonidae, an early offshoot and close relatives of palaeontinids.

Classification

Early Jurassic palaeontinids

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Palaeontina oolitica
(forewing)

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Palaeocossus jurassicus
(forewing)

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Prolystra lithographica

Late Jurassic palaeontinids

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Eocicada lameerei

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Limacodites mesozoicus

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Beloptesis oppenheimi

The family was first erected by the Austrian entomologist Anton Handlirsch in 1908. Like Butler, Handlirsch insisted that palaeontinids were members of lepidopteran Heteroneura (butterflies and moths). Palaeontinids were then only known mostly from poorly preserved specimens like Palaeontina and Eocicada. He claimed they were related to the extant family Limacodidae (slug moths). The English entomologist Edward Meyrick supported the lepidopteran conclusion, though he believed they belonged to the family Hepialidae (ghost moths) instead. He said "There is little doubt that it [i.e. Palaeontina oolitica] belongs to the Hepialidae."

The Belgian entomologist Auguste Lameere challenged this conclusion, claiming palaeontinids were more closely related to the extant family Cicadidae (cicadas). The English-Australian entomologist and geologist Robert John Tillyard supported Lameere's conclusion, noting that the wings of palaeontinid fossils lacked the characteristic scales of lepidopterans but instead had tubercules, pits, and cross-ridges like those found in modern cicadas. He also cited characteristics of wing venation that distinctly differs from that of lepidopterans.

Palaeontinidae are currently classified under the extinct superfamily Palaeontinoidea along with the families Dunstaniidae and Mesogereonidae. They are classified under infraorder Cicadomorpha of the hemipterans (true bugs).

The name Cicadomorphidae was once proposed as a replacement for the name Palaeontinidae in 1956 by the Australian entomologist J.W. Evans. This was because of Handlirsch's earlier insistence that the type species Palaeontina oolitica may not have been Hemipteran. However, Evans later conceded that retaining the name Palaeontinidae was preferable as the drawings Handlirsch based his conclusions on were from badly preserved specimens.

Evolution

Riek (1976) originally considered Palaeontinoidea to be the descendants of the family Cicadoprosbolidae (currently known as the family Tettigarctidae), insects believed to be transitional between the ancestral cicada-like family Prosbolidae and the modern family Cicadidae.

Wang et al (2009), however, notes that palaeontinoids more closely resemble prosbolids in agreement with earlier studies by Wootton (1971), Shcherbakov (1984), and Shcherbakov and Popov (2002). They conclude that palaeontinoids descended directly from the family Prosbolidae rather than from tettigarctids. Modern cicadas therefore, did not descend directly from Palaeontinidae.

Within Palaeontinoidea, the family Dunstaniidae (Upper Permian to Lower Jurassic of Australia, South Africa, and China) is ancestral to palaeontinids. Both are distinct from the only other member of the superfamily, the more primitive and specialized family Mesogereonidae (Upper Triassic of Australia and South Africa).

Distribution and geologic time range

File:Palaeontinidae Distribution (Late Jurassic).jpg

Paleogeographic representation of the Earth during the Late Jurassic showing the approximate locations of some palaeontinid fossil sites. 1 - Crato Formation, Brazil; 2 - Serra del Montsec, Spain; 3 - Baissa, Transbaikalia; and 4 - Yixian Formation, China.

Palaeontinids first appeared during the Rhaetian age of the Upper Triassic and became extinct during the Early Aptian age of the Lower Cretaceous (203.6 to 112.0 million years ago). They achieved their greatest diversity during the Jurassic period.

The earliest palaeontinid discovered, is the poorly known genus Asiocossus, based on a forewing fragment recovered from the Upper Triassic of Kyrgyzstan. Palaeontinid fossils are abundant in Eurasia and South America. Fossils have been recorded in Brazil, China, Russia, Germany, the Transbaikal region, Tajikistan, Turkmenistan, Kyrgyzstan, Kazakhstan, Spain, and the United Kingdom. Important localities for palaeontinid fossils include the Crato Formation Lagerstätte of Brazil and the Yixian Formation, Haifanggou (or Jiulongshan) Formation, and the Daohugou Beds of China.

Genera

The following is the list of genera classified under Palaeontinidae:

• †Abrocossus Wang & Zhang, 2007 in Wang et al. 2007a - Middle Jurassic, East Asia
• †Archipsyche Handlirsch, 1906–1908 - Late Jurassic, Central Europe
• †Asiocossus Becker-Migdisova, 1962 - Upper Triassic, Central Asia
• †Baeocossus Menon et al. 2005 - Early Cretaceous, Eastern South America
• †Beloptesis Handlirsch, 1906–1908 - Late Jurassic, Central Europe
• †Cicadomorpha Martynov, 1926 - Late Jurassic, Central Asia; Early Cretaceous North Asia
• †Colossocossus Menon et al. 2005 - Early Cretaceous, Eastern South America
• †Cratocossus Martins-Neto, 1998 - Early Cretaceous, Eastern South America
• †Daohugoucossus Wang et al. 2006b - Middle Jurassic, East Asia
• †Eocicada Oppenheim, 1888 - Late Jurassic, Central Europe
• †Eoiocossus Wang et al. 2006c in Wang et al. 2006c - (includes Papilioncossus Wang et al. 2007c) Middle Jurassic, East Asia
• †Gansucossus Wang et al. 2006b - Middle Jurassic, East Asia
• †Hamicossus Wang & Ren 2007ab - Middle Jurassic, East Asia
• †Ilerdocossus Gomez-Pallerola, 1984 - (includes Wonnacottella Whalley & Jarzembowski, 1985 and Liaocossus Ren et al., 1998) Early Cretaceous, Western Europe & East Asia
• †Limacodites Handlirsch, 1906–1908 - Late Jurassic, Central Europe
• †Martynovocossus Wang & Zhang 2008 in Wang et al. 2008 - (= Pseudocossus Martynov, 1931) Early to Middle Jurassic, North Asia; Late Jurassic, Central Asia
• †Miracossus Ren et al. 1998 - Early Cretaceous, East Asia
• †Montsecocossus Gomez-Pallerola, 1984 - Early Cretaceous, Western Europe
• †Neimenggucossus Wang & Zhang, 2007 in Wang et al. 2007a - Middle Jurassic, East Asia
• †Ningchengia Wang, Zhang & Szwedo, 2009 - (= Fletcheriana Evans, 1956 in partim) Middle Jurassic, East Asia
• †Pachypsyche Handlirsch 1906 - Early Cretaceous, Western Europe
• †Palaeocossus Oppenheim, 1885 - Early Jurassic, Central and North Asia
• †Palaeontina Butler, 1873 - Early Jurassic, Central and North Asia
• †Palaeontinodes Martynov, 1937 - (= Ijacossus Becker-Migdisova, 1950; Shcherbakov 1985) Early to Middle Jurassic, Central and North Asia; Middle Jurassic, Central Asia
• †Parawonnacottella Ueda, 1997 - Early Cretaceous, Eastern South America
• †Phragmatoecicossus Becker-Migdisova, 1949 - Early to Middle Jurassic, Central Asia
• †Phragmatoecites Oppenheim, 1885 - Early to Middle Jurassic, North Asia
• †Plachutella Becker-Migdisova, 1949 - Early to Late Jurassic, Central and Eastern Asia
• †Prolystra Oppenheim, 1888 - Late Jurassic, Central Europe
• †Protopsyche Handlirsch, 1906–1908 - Late Jurassic, Central Europe
• †Shurabocossus Becker-Migdisova, 1949 - Early to Middle Jurassic, Central Asia
• †Sinopalaeocossus Hong, 1983 - (= Quadraticossus Wang & Ren, 2007a) Middle Jurassic, East Asia
• †Suljuktaja Becker-Migdisova, 1949 - Early to Middle Jurassic, Central Asia
• †Suljuktocossus Becker-Migdisova, 1949 - (= Fletcheriana Evans, 1956 in partim) Early Jurassic, Central Asia; Middle Jurassic, North Asia
• †Turgaiella Becker-Migdisova & Wootton, 1965 - Jurassic, Central Asia
• †Valdicossus Wang, Zhang & Jarzembowski 2008 - Early Cretaceous, Western Europe
• †Yanocossus Ren, 1995 - Early Cretaceous, East Asia

Palaeontinidae incertae sedis

• †Cyllonium Westwood, 1854 - Early Cretaceous, Western Europe (too poorly preserved)
• †Palaeontinopsis Martynov, 1937 - Early Jurassic, Central Asia (nomen dubium)
• †Palaeontinopsis sinensis - Hong, 1986; Zhang, 1997 Middle Jurassic, East Asia
• †Fletcheriana jurassica - Zhang, 1997
• †Fletcheriana magna - Riek, 1976

See also

• Prehistoric Lepidoptera
• Prehistoric insects

External links

• Data related to Palaeontinidae at Wikispecies
• Media related to at Wikimedia Commons