Hungary’s first fossil wasps: an unprecedented insight into the fauna of a marshy environment of the European Cretaceous

Article in Cretaceous Research
𝐴𝑗𝑘𝑎𝑛𝑒𝑠𝑖𝑎 ℎ𝑎𝑟𝑚𝑖𝑛𝑐𝑖𝑝𝑧𝑖𝑙𝑜𝑛𝑖 gen. et sp. nov.

Manuel Brazidec and Vincent Perrichot (Université de Rennes 1, Géosciences Rennes) and their colleagues Márton Szabó, Imre Szenti, Ákos Kukovecz and Attila Ősi published an article in August 2022 in the journal Cretaceous Research describing the first fossil hymenoptera in Hungary.

Becoming an inclusion in amber is the most favorable fossilization medium for terrestrial invertebrates. Insects in particular, once trapped in a resin flow, are thus preserved in three dimensions, sometimes including internal structures. There are many deposits in the world, including in France, but the most studied and fossiliferous are those of the Baltic (Eocene, 35 million years) and Myanmar (Cretaceous, 100 Ma).

Fossilisation des insectes dans l'ambre

Ajkaite is a variety of Late Cretaceous amber, collected in Hungary. The amber deposits of this period are not exceptional around the world, but most come from layers dated from the Cenomanian (~100 to 94 Ma). The ajkaite is quite unique by its age: the Santonian (~86 to 83 Ma). Only a few Santonian deposits, like those of Piolenc, in the Vaucluse, but especially Taimyr, in Russia, have delivered arthropods of this age. Ajkaite is found in the coal mines of Ajka, in the Bakony Massif (Western Hungary). The sedimentary facies of Ajka reflects a marshy or lacustrine deposition environment.

 

faciès sédimentaire d’Ajka

 

 

The fossil potential of this deposit has been known for about fifty years but has never been fully exploited. So far, only two biting midges in 1997 (Adelohelea magyarica and Leptoconops clava), one spider (Hungarosilia verdesi) and one beetle (Ajkaelater merkli) have been formally described this year.

Márton Szabó and his team (Hungarian Natural History Museum, Department of Paleontology) provided Vincent Perrichot and Manuel Brazidec with three Hymenoptera, the first known of the deposit. Two belong to the Bethylidae family, a group of stinging wasps present on all continents at present and the third is identified as a Spathiopterygidae, an exclusively extinct family.

Just for fun ...

The first Bethylidae belongs to the Pristocerinae subfamily and represents a new genus: Ajkanesia harmincipziloni gen. and sp. nov..
   The species name - Ajkanesia harmincipziloni - comes from the Hungarian rock band 30Y, many of whom spent their childhood in Ajka! The second Bethylidae is also the second Santonian representative of its subfamily, the Scleroderminae. Its binomial name, Amissidigitus belae gen. and sp. nov. is a pun: the literal translation means "Béla’s lost toe"! Béla Szabó was Márton Szabó’s grandfather and lost a toe while working in the Ajka coal mines Finally, the Spathiopterygidae Spathiopteryx soosi sp. Nov., is dedicated to geologist Miklós Soós, founder of the Hungarian Dinosaur Foundation and an ardent supporter of ajkaite research. The youngest representative of this family was so far dated 90 Ma: the extinction of the Spathiopterygidae is therefore more recent than estimated

It is not surprising to find these two families in the ajkaite. Bethylidae are known to parasitize larvae in cryptic environments, such as trunks or branches, which could be found in Ajka marshes and lakes, while Spathiopterygidae appear to be very well represented in wet ecosystems. These specimens offer an unprecedented insight into the Hymenoptera fauna of the western archipelago of the ancient Tethys Ocean. Ajkaite is a promising source for the study of Santonian terrestrial arthropods.


Référence
Szabó, M., Brazidec, M., Perrichot, V., Szenti, I., Kukovecz, A., Ősi, A., 2022. A unique record of the Late Cretaceous of East-Central Europe: the first fossil wasps (Hymenoptera: Bethylidae, Spathiopterygidae) from the ajkaite amber (Bakony Mts., western Hungary). Cretaceous Research 2022, 105314. doi:10.1016/j.cretres.2022.105314

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