| Titanoptera | |
|---|---|
 | |
| Reconstruction ofGigatitan | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Infraclass: | Neoptera |
| Cohort: | Polyneoptera |
| Order: | †Titanoptera |
| Families | |
Titanoptera is an extinct order ofneopteraninsects from lateCarboniferous toTriassic periods.[1] Titanopterans were very large in comparison with modern insects, some having wingspans of up to 36 centimetres (14 in) or even 40 centimetres (16 in).[2][3]
Titanopterans are related to moderngrasshoppers, but were much larger, had proportionally weaker hindlegs that could not allow the animals to leap, and grasping forelegs and elongatedmandibles. Another distinctive feature was the presence of prominent fluted regions on the forewings, which may have been used instridulation. The general shape and anatomy of the titanopterans suggests that they were predators.[2]
An examination of a fossil of the oldest titanopteran genus,Theiatitan, seems to indicate that titanopterans did not utilize stridulation (unlike modern orthopterans), but rather used flashes of light from wing displays and crepitation, moving their wings to produce sound. The authors argue that stridulation, crepitation, castanet signaling or light flash alone do not fully explains the diversity of structures observed in Titanoptera, and note that both sexes seem to have the fluted region on the forewing.Theiatian is 50 Ma older than the previous oldest species of Titanoptera, and thusTheiatitan would be the oldest known insect with a wing structure specialized for communication.[1]
Some titanopterans may have been able to only glide, not fly, such asGigatitan vulgaris. The hind wing area of it is almost the same as that ofPseudophyllanax imperialis, one of the largest modernOrthoptera, and a poor flier, butGigatitan is larger in volume. All known hind wings of Titanoptera, whatever their sizes, have quite reducedvannus, while most extant flying Orthoptera have large ones.[1]
Other thanTheiatitan, reliable records of titanopterans are known fromKyrgyzstan,Australia andSouth Korea. Considering some possible records fromRussia as well, titanopterans possibly had a circum-Tethys distribution.[3]
There is controversy regarding the classification of Titanoptera. Titanoptera was previously thought to be related toGeraridae (includingGerarus), but it is no longer supported.[4] Béthoux (2007) considered that genera in Titanoptera should be included inOrthoptera, and divided from extinct orthopteran familyTchomanvissidae.[5] But later study considered that the relationships between Titanoptera and Tcholmanvissiidae remain controversial.[1] Three genera known fromPermian,Permotitan,Deinotitan,Monstrotitan possibly not belong to Titanoptera.[1] Although the genusJubilaeus originally belonged to Mesotitanidae, but it is later considered to belong to Tcholmanvissiidae.[5][6]Steinhardtia was originally attributed to Titanoptera, but as fossil does not show the venational structures of the order Titanoptera, and it is even possible to be misidentification of plant fossil, possiblyfern.[1]
OrderTitanoptera
