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, RenĂ© 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

Popular Posts

Java ruellia (Ruellia treubiana)

Java ruellia ( Ruellia treubiana ) is a species of plant in the Acanthaceae, herbaceous, erect, up to 35 cm tall, cylindrical and green stems, fibrous and white roots. R. treubiana has leaves sitting opposite each other with long stalks up to 1 cm. The leaves are oval, up to 6.5 cm long, up to 4 cm wide, pointed at the tip, a main vein in the middle with many small pinnate veins and flat margins. Fan-shaped flowers with five fins, bluish white, up to 3.5 cm long and up to 2.5 cm wide. This species grows on the forest floor in narrow colonies, under teak forests that tend to be shady, on the edge of puddles, on the edge of roads etc. Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Lamiales Family: Acanthaceae Subfamily: Acanthoideae Tribe: Ruellieae Subtribe: Ruelliinae Genus: Ruellia Species: Ruellia treubiana

Pygmy groundcherry (Physalis minima)

Ceplukan or pygmy groundcherry ( Physalis minima ) is a plant species in the Solanaceae, a pantropical perennial herb, 50 cm high, green in color, grows in wet or semi-wet areas, the fruit is edible and has a pleasant taste, is often used as an anti-cancer, analgesic and anti-inflammatory. P. minima has an erect trunk with many branches, is square with sharp angles, 20-50 cm high, bright green and juicy. The branching produces two or three new stems and becomes the point for producing leaves and fruit. The leaves have a smooth surface, hairless, plain or serrated edges, 2.5-12 cm long, light green color and pointed tips. The stalk is long and continues to be a bone in the center of the leaf with some lateral veins. Bell-shaped flowers with five corners, cream to yellow in color with brown plots on the inside and white pistils. The fruit is yellowish green and packed in a thin covering that turns brown and falls to the ground when ripe. Pygmy groundcherry grows wild in forest edges, ...

Redflower ragleaf (Crassocephalum crepidioides)

Sintrong or ebolo or thickhead or redflower ragleaf ( Crassocephalum crepidioides ) are plant species in Asteraceae, terma height 25-100 cm, white fibrous roots, generally grow wild on the roadside, yard gardens or abandoned lands at altitude 200- 2500 m. C. crepidioides has erect or horizontal stems along the soil surface, vascular, soft, non-woody, shallow grooves, green, rough surface and short white hair, aromatic fragrance when squeezed. Petiole is spread on stems, tubular and eared. Single leaf, spread out, green, 8-20 cm long, 3-6 cm wide, longitudinal or round inverted eggshell with a narrow base along the stalk. Pointed tip, flat-edged or curved to pinnate, jagged rough and pointed. The top leaves are smaller and often sit. Compound flowers grow throughout the year in humps that are arranged in terminal flat panicles and androgynous. Green cuffs with orange-brown to brick-red tips, cylindrical for 13-16 mm long and 5-6 mm wide. The crown is yellow with a brownish red...