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

Screw tree (Helicteres isora)

Screw tree ( Helicteres isora ) is a species of plant in the Malvaceae family. It is a shrub or small tree, up to 8 meters tall. It has gray bark and alternate leaves, up to 22 cm long and 17 cm wide, oval in shape, with serrated edges and hairs. The flowers are red or white and reach a total length of 5.5 cm. The fruit is green when unripe, brown or gray when dry, twisted, spiral-shaped, and pointed at the tip. The seeds are black or brown, shiny, and diagonal, triangular, or rectangular. TAXON Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Malvales Family: Malvaceae Subfamily: Helicteroideae Tribe: Helictereae Genus: Helicteres Pluk. ex L. in Sp. Pl.: 963 (1753) Species: Helicteres isora L. in Sp. Pl.: 963 (1753) HETEROTYPIC SYNONYMS Helicteres baruensis var. ovata DC. in Prodr. 1: 476 (1824) Helicteres chrysocalyx Miq. ex Mast. in J.D.Hooker, Fl. Brit. India 1: 365 (1874) Helicteres corylifolia Buch.-Ham. ex Dillwyn in Rev. Hortus Malab....
Read more

Coromandel (Asystasia gangetica)

Coromandel ( Asystasia gangetica ) is a species of plants in Acanthaceae, perennials, vines and branching that are widely found on the edges of roads, shrubs and gardens, resistant to shade, used as fodder, especially cattle, goats and sheep, treatment, conservation of land and ornamental plants. A. gangetica has a height of 88-95 cm, rectangular-shaped stem, brownish green or purplish green, taproot and can emerge from branches. Petiole has a length of 0.5-6 cm. Ellipse-shaped leaves, unifoliate, green or dark green, arranged facing each other and do not have stipules. Leaves have a length of 8.5 cm, width 4.9 cm, area 69.42 cm3, length and width ratio is 1.8:1, heart-shaped base and taper front end, rough surface, flat edge, a main bone and 4 -6 lateral veins on each side. Coromandel produces flowers after 4 weeks to 2 months. Compound flowers, lined up on one side with a length of up to 25 cm. Flower stalks have a length of up to 3 mm. Trumpet type, white with a bottom stran...
Read more

Wild durian (Cullenia exarillata)

Wild durian ( Cullenia exarillata ) is a species of plant in the Malvaceae, a tall tree with smooth, greyish-white bark, peeling on older trees, a straight trunk, horizontal branches and often with a series of knob-like tubercles for flower and fruit attachment. C. exarillata has young branches and the underside of the leaves is covered with golden brown peltate or shield-like scales. The leaves are single, alternate, glabrous, glossy green on the upper side and covered with silvery or orange peltate scales on the underside. Hermaphroditic flowers are tubular and also covered with golden brown scales, 4-5 cm long and cream or reddish brown in color. Flowers have no petals, formed of tubular bracteoles and tubular calyxes, 5-lobed. Fruit is round, 10-13 cm in diameter, covered with thorns and clustered along the branches. Many seeds, reddish brown, 4-5 cm long and 2-3 cm wide. The seeds are enclosed by a fleshy, whitish aril. The fruit splits open when ripe and dries to release the s...
Read more