Stenophlebiidae

Adult Body The head is similar to that of Recent Gomphidae with two large and globular compound eyes that are distinctly separated. The three ocelli are arranged in a triangle on the globular vertex. The mandibles are strong. The legs have short and strong spines. Wings and wing venation The largest species Stenophlebia amphitrite reached a wingspan of about , while the smallest species Hispanostenophlebia barremiana reached only a wingspan of about . Stenophlebiidae are distinguished by the following set of eight derived wing characters (synapomorphies): (1) a long not zigzagged secondary longitudinal convex vein in the postdiscoidal area, parallel to MP, the base of this vein being just distal of the discoidal triangle; (2) Cr long or very long, covering more than one or two cells between RA and RP; (3) pterostigma shifted basally; (4) pterostigma very long; (5) hindwing subdiscoidal space transverse and crossed by two veins or more; (6) the four wings elongate and more or less falcate; (7) forewing discoidal triangle long transverse; (8) numerous and well defined straight intercalary secondary longitudinal veins reaching posterior wing margin. Furthermore they share the following four synapomorphies with Prostenophlebiidae in the superfamily Stenophlebioidea: (1) a long and not zigzagged (or slightly zigzagged) secondary longitudinal convex vein in postdiscoidal area, parallel to MP, the base of this vein being about two or three cells or just distal of discoidal triangle; (2) a long and not zigzagged concave Mspl; (3) oblique vein "O" absent; (4) wings elongate. Larva Fossil larvae of this extinct family have not been formally described yet, but Bechly (2007) suggested that the Nothomacromia larvae from the Lower Cretaceous Crato Formation of Brazil may be the larvae of Cratostenophlebia. ==Classification==

The family group taxon was established by Needham (1903) as subfamily Stenophlebinae (sic) of the extinct damsel-dragonfly family Heterophlebiidae. It was emended and elevated to family rank Stenophlebiidae by Handlirsch (1906). The family contains 9 described genera with a total of 18 species: • Stenophlebia? lithographica (Giebel, 1857) - (nomen dubium; type locality: Eichstätt, Germany; type horizon: Upper Jurassic, Malm zeta 2b, Lower Tithonian / 150 mya, Hybonotum Zone, Solnhofener Plattenkalk Formation; holotype: at University of Heidelberg, probably lost; size: wings about 55 mm; maybe a synonym of S. phryne or S. latreillei) • Stenophlebia phryne (Hagen, 1862) - (type locality: Eichstätt, Germany; type horizon: Upper Jurassic, Malm zeta 2b, Lower Tithonian / 150 mya, Hybonotum Zone, Solnhofener Plattenkalk Formation; lectotype: MCZ 6212 at Harvard University; size: forewing 55.0 mm) • Stenophlebia rolfhuggeri Bechly et al., 2003 • Cretastenophlebia mongolica Fleck et al. 2003 - (type locality: Bon Tsagaan, Bayanhongor Aimak, Central Mongolia; type horizon: Lower Cretaceous, Hauterivian/Barremian / 129 mya, Dzun-Bain Formation; holotype: isolated male hindwing no. PIN 3559/10180 at Palaeontological Institute Moscow; size: hindwing 40.0 mm) • Genus Gallostenophlebia Nel et al. 2015 • Gallostenophlebia incompleta Nel et al. 2015- (Upper Cretaceous (Cenomanian); Jaunay-Clan locality, Vienne, France) • Genus Hispanostenophlebia Fleck et al., 2003 • Genus Mesostenophlebia Fleck et al., 2003 ==Phylogeny==

The set of shared derived characters listed in the description section above demonstrate that Stenophlebiidae is clearly a monophyletic group (clade). However, these hypotheses have been refuted by Fleck et al. (2003). The phylogenetic position of Stenophlebiidae according to Bechly (1996, 2007) and Fleck et al. (2003, 2004): }} }} }} }} }} }} }} }} }} }} ==Biology==

Next to nothing is known about the ecology and behavior of Stenophlebiidae, but it probably was quite similar to Recent odonates. The shape of the wings suggests that they were slow flyers that fed on smaller flying insects. The females probably inserted their eggs into plants in or close to the water. ==Geographical and geological distribution==

The fossil record of this family ranges from Upper Jurassic of Germany (Solnhofen Plattenkalk, Nusplingen limestones) and Kazakhstan (Karabastau Svita) to the Lower Cretaceous of Brazil (Crato Formation), Mongolia (Bon Tsagaan), Spain (Las Hoyas), and England (Durlston Formation) to the Upper Cretaceous (Cenomanian) of France ==History==

Larger revisions of this family have been provided by Nel et al. (1993) and Fleck et al. (2003). Earliest finds The first stenophlebiid fossil was described as "Agrion" latreillei by Germar (1839) from the Upper Jurassic Solnhofen Plattenkalk of Germany. Notable specimens Beside the important type specimens there are also several exceptionally well preserved fossils that contribute to our knowledge of the morphology of Stenophlebiidae. These include specimens of Stenophlebia amphitrite and Stenophlebia latreillei in several private fossil collections. ==References==