Sinoparathyrea Pan, Chang & Ren

Pan, Xiaoxiong, Chang, Huali, Ren, Dong & Shih, Chungkun, 2011, The first fossil buprestids from the Middle Jurassic Jiulongshan Formation of China (Coleoptera: Buprestidae), Zootaxa 2745, pp. 53-62 : 54-55

Genus Sinoparathyrea Pan, Chang & Ren , gen. nov.

Etymology. From Greek prefix “ sin -” (meaning China) and “ parathyrea ” (a generic name of this subfamily).

Type species. Sinoparathyrea bimaculata sp. nov.

Species included. Sinoparathyrea bimaculata sp. nov., Sinoparathyrea gracilenta sp. nov., and Sinoparathyrea robusta sp. nov.

Diagnosis. Body medium sized, about 13−18 mm long, subcylindrical, with head nearly as wide as anterior margin of pronotum. Pronotum about 1.6 times wider than long, lateral margins weakly arched at anterior 3/4, then arcuately expanded to posterior margin, basolateral angles acute, the widest part at its base. Elytra more than 3.0 times as long as wide, the widest part at the middle; lateral margins weakly arcuate in anterior 2/3, then somewhat arcuately narrowed to obtuse apex, the last ventrite of abdomen broadly rounded at apex.

Distribution. The genus is only known from the Middle Jurassic Daohugou beds, Jiulongshan Formation, Ningcheng County, Inner Mongolia in China.

Remarks. The new genus can be assigned to the family Buprestidae due to the following characters: (1) head retracted into the prothorax; (2) metasternum with transverse suture; (3) elytra long, gradually narrowed to the apex; (4) procoxae, mesocoxae rounded, metacoxae transverse, short laterally; (5) abdomen with five visible ventrites. The attribution of the new genus to the subfamily Parathyreinae Alexeev, 1993 is based on its subcylindrical body, the straight paracoxal suture, its rounded head, the elytra with nine distinct longitudinal striae, and the anterior margin of the metacoxae perpendicular to the longitude axis of body. The typical character of the subfamily Parathyreinae is the straight paracoxal suture which in recent subfamilies is anteriorly strongly attenuate trapeziform in the middle ( Alexeev 1993).

At present, the fossil subfamily Parathyreinae includes fifteen fossil genera: Acmaeoderimorpha Alexeev, 1993, Ancestrimorpha Alexeev, 1993, Crassisoma Alexeev, 1993 , Cretofrontolina Alexeev, 2009, Cretothyrea Alexeev, 1996 , Elegantella Alexeev, 1993 , Karatausia Alexeev, 1993, Mongoligena Alexeev, 1993, Mongolobuprestis Alexeev, 1993, Paleas Alexeev, 1993, Paramongoligena Alexeev, 1993, Parathyrea Alexeev, 1993, Pseudomongoligena Alexeev, 2000, Stigmoderimorpha Alexeev, 1993, and Umerata Alexeev, 1993.

The new genus differes from all the other genera of this subfamily in having the combination of the following characters states: head nearly as wide as anterior margin of pronotum; pronotum about 1.6 times wider than long, lateral margins weakly arched at anterior 3/4, then arcuately expanded to posterior margin, basolateral angles acute, the widest part at its base; the widest part of the elytra at the middle, lateral margins weakly arcuate in anterior 2/3, then somewhat arcuately narrowed to obtuse apex, and the last ventrite of abdomen broadly rounded at apex.

Among these genera, the new genus is more similar to the genus Parathyrea Alexeev, 1993 in the shape of pronotum, but differs from the latter in having: (1) much wider head; (2) posterior angles of pronotum more acute; (3) apex of elytra obtuse; (4) the apex of last abdominal ventrite more broadly rounded.

The genera with head nearly as wide as anterior margin of pronotum are Acmaeoderimorpha Alexeev, 1993, Karatausia Alexeev, 1993, Mongoligena Alexeev, 1993 and Paleas Alexeev, 1993, the new genus differs from them by having: (1) pronotum about 1.6 times as wide as long; (2) lateral pronotal margins weakly arched at anterior 3/4, then arcuately expanded to posterior margin, basolateral angles acute; (3) apex of elytra obtuse; (4) the apex of last abdominal ventrite more broadly rounded.

The genera with the similar shape of elytra, the apex of elytra obtuse and the apex of last abdominal ventrite broadly rounded are Elegantella Alexeev, 1993 , Umerata Alexeev, 1993 and Pseudomongoligena Alexeev, 2000, but the new genus differs in shape of pronotum, the lateral margins weakly arched at anterior 3/4, then arcuately expanded to posterior margin, basolateral angles acute, the widest part at its base.

The new genus is similar to the genus Cretothyrea Alexeev, 1996 in the apex of last abdominal ventrite broadly rounded, but differs form the latter in having: (1) lateral pronotal margins weakly arched in anterior 3/4, then arcuately expanded to posterior margin, posterior angles acute; (2) the widest part of the pronotum at its base; (3) the widest part of the elytra at the middle, apex obtuse.

Compared with the genera Ancestrimorpha Alexeev, 1993, Crassisoma Alexeev, 1993 and Stigmoderimorpha Alexeev, 1993, the new genus has the following unique characters: (1) head large, width of head nearly as long as that of anterior margin of pronotum; (2) lateral pronotal margins weakly arched at anterior 3/4, then arcuately expanded to posterior margin, basolateral angles acute; (3) the apex of last abdominal ventrite broadly rounded.

In addition, the new genus differs from Mongolobuprestis Alexeev, 1993, Paramongoligena Alexeev, 1993 and Cretofrontolina Alexeev, 2009 in having acute pronotal basolateral angles, obtuse elytra apex and the apex of last abdominal ventrite broadly rounded.