Skip to main content

Henrik Madsen's earwig (Apachyus madseni), 55 million year old fossil from Ypresian Fur Formation in Denmark

Dlium Henrik Madsen's earwig (Apachyus madseni), 55 million year old fossil from Ypresian Fur Formation in Denmark

NEWS - Henrik Madsen's earwig (Apachyus madseni Simonsen & Rasmussen sp. nov.) is reported based on a nearly complete 55 million year old fossil from the Ypresian Fur Formation in northwestern Denmark. The new fossil is not only a new addition to the mo-clay fauna, but also an extension of its historical biogeographic range.

The last few decades have seen an increasing focus on the richness of the insect fossil record found in the Ypresian Fur Formation in northwestern Denmark. One insect order that has to some extent been spared from this surge in taxonomic knowledge from the site is the Dermaptera commonly known as earwigs.

Now, Thomas Simonsen from the Natural History Museum Aarhus and Jan Rasmussen from the Mors Museum and colleagues report a new species of Dermaptera in Apachyus Serville as the first fossil record in the Apachyidae which currently consists of two species-poor genera and is distributed across the Indian Subcontinent, Southeast Asia, Australia and Central Africa.

A. madseni has a total length (excluding cerci): 18.8 mm. Head subtriangular, prognathous with clearly preserved mandibles; antennae not preserved; eyes discernible; anterior cervical sclerite well preserved and small; posterior cervical sclerite poorly preserved but appearing larger than the anterior cervical sclerite. Pronotum well preserved, sub-circular with longitudinal groove, femur and tibia of foreleg poorly preserved.

Mesothorax preserved with femur and tibia of both midlegs poorly preserved, tegmen poorly preserved but discernible, subrectangular. Metathorax with femur of right hindleg poorly preserved. Hind wings preserved with squama clearly visible.

Abdomen well preserved with most segments discernible; segment 10 well preserved and broad, with broad, subrectangular and smooth terminal squamopygidium obscuring the pygidium; cerci well preserved, simple, arcuate/broad sickle-shaped, widely separated at base, strongly curved around the tip of the abdomen.

The eponymous name honors Henrik Madsen who has been collecting fossils in the Fur Formation of Denmark for more than three decades. A. madseni can be distinguished from all other Apachyus by its broad and short squamopygidium with a smooth and slightly convex distal margin.

A. madseni is the second species of Dermaptera described from the Fur Formation and the first fossil representative of Apachyidae to be described globally. The family currently consists of 15 current species in two genera (13 in Apachyus and 2 in Dendroiketes) and A. madseni.

The current species are distributed in Central Africa (3 species) and the remainder from India to the Philippines and Australia. The discovery of A. madseni represents an expansion of the range of Apachyidae, indicating that the distribution of a family does not necessarily reflect its past distribution or biogeographic origin.

Original research

Thomas J. Simonsen, René L. Sylvestersen, Kent Olsen & Jan A. Rasmussen (2024). Apachyus madseni (Dermaptera: Apachyidae) sp. nov. from the Ypresian Fur Formation of Denmark: the first fossil record of the enigmatic earwig family Apachyidae. Palaeoentomology 007 (5): 638–644, DOI:10.11646/palaeoentomology.7.5.7

Dlium theDlium
Labels:

Popular Posts

Fern tree (Filicium decipiens)

Kerai payung or fern tree ( Filicium decipiens ) is a plant species in Sapindaceae, a tree that is always green with thick and round canopies such as umbrellas, 5-10 m high but old specimens in nature can exceed 25 m, upright stems, gray bark ash to reddish brown, smooth when young but rough and cracked when mature. F. decipiens has large, fern-like and conspicuous leaves, up to 40 cm long and made of elongated longitudinal, glossy green leaflets arranged in pairs. Leaves on stems with a length of 3-10 cm, alternating, imparipinnat, 15-30 cm long and 12-15 cm wide. Winged rachis with 6-12 pairs of opposite or sub-opposite leaflets, sessile, oblong-lanceolate with full margins and slightly wavy, 6-12 cm long and 1-3 cm wide, coriaceous, dark green and glossy above. Flowers grow on stems with a length of 7 cm as panicles for lengths of 15-30 cm which carry many small, unisexual flowers and hermaphrodites with a diameter of 0.4-0.6 cm. Pentaparted petals with imbricate ovate lobes, fi...
Read more

Porang (Amorphophallus muelleri)

Porang or iles-iles ( Amorphophallus muelleri ) is a plant species in Araceae, the petiole is a pseudo stem with a height of 40-180 cm, 1-5 cm in diameter, round, green or purple with irregular white spots, each branching point grows brown bulbil and yellow bulb. A. muelleri has all leaves or stems or stems that are light green to dark green or gray and has greenish-white patches, smooth or smooth surface. The leaves are elliptical in shape with pointed leaf tips, smooth and wavy surface. When flushing has 3, 4-5, 5-6 and finally 6 minor leaves branching with 3 minor petioles. Young leaves have light purple or green edges and will end in yellow and 0.3-0.5 mm wide. The whole canopy is 50-150 cm wide. The stems grow above the tubers with a diameter of 25-50 mm and a height of 75-175 cm. Tubers have a brownish yellow or gray color on the outer surface and brownish yellow on the inside, are slightly oval in shape, fibrous roots, weigh 450-3350 grams, smooth tissue, 4-5 months of dormanc...
Read more

Golden-armed mantis (Hierodula venosa)

Golden-armed mantis ( Hierodula venosa ) is an animal species in the Mantidae, winged praying mantis with females 65-75 mm long and males 45-65 mm, large but not the largest in the genus Hierodula and generally bright yellow with green and chocolate variations. H. venosa has a fully rotating head. The head is dominated by a pair of very large and brownish yellow eyes. The jaw forms a triangle. The back is very wide with thickened margins. A pair of long antennas. Wide wings with rounded tips, striped surface, thick margins, two small white plots on the right and left. The belly is large and jointed, curved downward, the upper part is completely covered by the wings, but partially visible from the side. The pair of forelegs are large and have three segments. The upper segment has rows of spikes on the front and back. The middle segment has a row of many spines on the back and a black tip. The third segment has a row of many spines, long, black and tipped with a long palm. The middle ...
Read more