in Jurassic and Cretaceous Stratigraphy

Earth Science Frontiers, Vol. 17, Special Issue, Aug. 2010 ISSN 1005-2321
186
The Major Diversification of Cicadomorpha in the Jurassic
(Insecta: Hemiptera)
Bo Wang 1 , Jacek Szwedo 2 , Haichun Zhang 1 , Yan Fang 1
1. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of
Sciences, Nanjing 210008, China (E-mail: savantwang@gmail.com; bowang@nigpas.ac.cn)
2. Museum and Institute of Zoology, Polish Academy of Sciences, 64, Wilcza Street, PL00-679 Warsaw, Poland
(E-mail: szwedo@miiz.waw.pl)
Representatives of the suborder Cicadomorpha
(Insecta: Hemiptera) are among the most common
insects nowadays. This ancient group was originated
in the Permian and prevailing in the Mesozoic.
However, our knowledge and understanding of its
early evolution are far from complete. The number,
status and phylogenetic relationships of their super-
families are also in debate (Evans, 1964; Hamilton,
1992; Blocker, 1996; Dietrich, 2002). The studies of
fossils are very important for reconstructing the evo-
lution of Cicadomorpha, because they contribute
significantly in valuable information to the time of
origins and extinctions, provide a means to estimate
the palaeodiversity and reveal trends in the evolution
of the morphological disparity. The Jurassic is a period
when the rapid evolution and diversification occurred
in the major Cicadomorpha lineage (Clypeata). Re-
cently discovered fossils provide new insight into the
early evolution of Cicadomorpha in the Jurassic.
In the Jurassic, Cicadomorpha were represented
by superfamilies: Prosboloidea (Dysmorphoptilidae),
Palaeontinoidea (Palaeontinidae), and Clypeata: Hyli-
celloidea (Hylicellidae), Cicadoidea (Tettigarctidae),
Cercopoidea (Procercopidae and a new family) and
Membracoidea (Karajassidae and probably the earliest
Cicadellidae). Dysmorphoptilidae, prevailing in the
Triassic, is a rare group in the Jurassic, while other
groups are rich during this period.
Palaeontinidae were common large arboreal
insects, often found in the Jurassic deposits. This
family was derived from Dunstaniidae in the Late
Triassic, and went into its most prosperous stage in the
Middle Jurassic, and became extinct in the mid-
Cretaceous (Wang et al., 2009). The latest Jurassic
Palaeontinidae from Solnhofen and most of Creta-
ceous Palaeontinidae form a monophyletic group. A
rapid diversification from ancient to more derived
Palaeontinidae took place during the Late Jurassic
times. Early Palaeontinidae declined sharply in the
Late Jurassic, probably owing to the rise of newly
evolved insectivorous animals like small pterosaurs,
early birds and mammals. Late Palaeontinidae with
better flight ability survived and became a dominant
insect group during latest Jurassic times.
Hylicellidae is a family weakly known in terms of
taxonomic diversity and morphological disparity, with
fossil record from Triassic to mid-Cretaceous. This
group consists of three subfamilies: Hylicellinae,
Archijassinae (its systematic position is under debate)
and Vietocyclinae. The first subfamily is just reported
from the Triassic. Archijassinae are relatively rich in
the Early Jurassic deposits of Eurasia, while Vieto-
cylinae are abundant in the Eurasian Jurassic deposits.
The superfamily Hylicelloidea (including Hylicellidae
and Triassic Chiliocyclidae) is clearly a paraphyletic
group, and requires detailed revisions. It is believed to
be an ancestral unit for Cercopoidea, Cicadoidea,
Myerslopioidea and Membracoidea (Shcherbakov,
1996; Szwedo et al., 2004). This superfamily and all
four derived groups are grouped into Clypeata.
Clypeata are characteristic, among other features, of
strong development of frontoclypeus, containing
strong salivary pump muscles. In contrast to phloem-
feeding Fulgoromorpha, ancestral Clypeata were
xylem-feeders, presenting numerous particular mor-
phological and physiological (as their recent
descendants) adaptations to such kind of food. They
also retained the median ocellus and primary segmen-
tation of the antennal flagellum, which were present in
earliest representatives of recent Clypeata. Besides the
modification of head, ancestral Clypeata probably
possessed simple tymbals and good jumping ability
(Hoch et al., 2006).
Tettigarctidae is the earliest representative of
Cicadoidea, with the earliest record from the latest
Triassic. They were continuously diversifying during
Jurassic times, and were ancestors of extant Tetti-
garctidae (two relic species in Australia and Tasmania)
and Cicadidae. Most of Jurassic Tettigarctidae pre-
sented an elliptical forewing with broad costal area
and clavus; whereas extant Tettigarctidae have ellip-
tical forewing with narrow costal area and reduced
clavus. This evolutionary trend is similar to that of
Mesozoic Palaeontinidae, and probably is related to an
improvement of flight ability. Tettigarctids could not
sing like extant singing cicadas because of the absence
of opercula and tympana. The short hind legs of Jura-
ssic Tettigarctidae suggest that they lost the jumping
ability, and the unmodified forelegs of adults indicate
that their nymphs probably were not hypogeic.
Procercopidae is very weakly known group,
which is believed to be ancestral of extant families of