Belongs within: Staphylinoidea.
The Agyrtidae are a group of beetles found primarily in northern temperate regions, associated with decaying organic material. The mandible commonly lacks preapical teeth though one or two large preapical teeth are present in members of the subfamily Pterolomatinae (Peck 2001).
Characters (Peck 2001): Oval to oblong-elongate, slightly flattened; brownish, usually shiny. Head projecting or deflexed; eyes conspicuous, usually protruding; frontoclypeal suture distinct. Antennae usually ending in distinct four- or five-segmented club, sometimes almost filiform or weakly clubbed; antennal sensilla usually located in apical grooves on club segments; antennal insertions more or less exposed. Thorax with pronotum larger than head. Pronotum with complete lateral edges, notosternal suture distinct. Prosternum short in front of coxae, bearing narrow but complete intercoxal process. Procoxae transverse, projecting, subcontiguous, with large, exposed trochantins; procoxal cavities narrowly open posteriorly and open internally. Mesocoxae narrowly separated. Elytra completely covering abdomen; punctation striate, as nine or ten longitudinal rows of punctures; epipleura well developed and complete, or extending to posterior four fifths. Metacoxae barely excavate mesally, contiguous, extending laterally to meet elytra. Hindwing with large, discrete jugal lobe, four anal veins, and simple, concave and convex, transverse folds; occasionally absent. Abdomen with five (or rarely six) visible abdominal sterna; lateral portions of sternum 2 present beneath the metacoxae. Intersegmental areas lacking pattern of microsclerites. Several basal terga membranous. Aedeagus may or may not have separate basal piece; parameres may be vestigial, fused, or absent. Larva campodeiform; with moderately sclerotised terga and sterna; mandibles bearing several apical teeth; prostheca narrow and acute, associated with brush of hairs; mandibles possessing large and tuberculate molar part with dorsal and ventral rows of denticles; maxilla with distinct galea and lacinia; galea usually fringed; labium with strongly bilobed ligula; six ocelli on each side of head; urogomphi two-segmented, often with multiannulate apical segment. Spiracles placed in posterolateral emarginations of terga. Abdomen segment ten elongate and cylindrical, with eversible membranous lobes bearing numerous minute hooks.
Agyrtidae [Agyrtinae, Agyrtini]
| i. s.: MesecanusP01
| Lyrosoma Mannherheim 1953B14, P90 [Lyrosominae]
| |--L. opacum Mannerheim 1853B14
| `--L. pallidumB14
|--+--Ipelates Reitter 1884MW15, P90 (see below for synonymy)
| | `--I. latus (Mannerheim 1852)P90, MP79 [=Necrophilus latusMP79, Pelates latusMP79, Pelatines latusMP79]
| `--NecrophilinaeMF15
| |--Zeanecrophilus thayeraeLC20
| `--Necrophilus Latreille 1829MW15, P90 (see below for synonymy)
| |--N. hydrophiloides Guérin-Méneville 1835GN09
| |--N. pettitii Horn 1880P01
| |--N. prolongatusR60
| `--N. subterraneus (Dahl 1807)B14
`--+--Agyrtes Frölich 1799LC20, P01 [incl. Agyrtecanus Reitter 1901P01, Lendomus Casey 1924P01]
| |--A. bicolorLC20
| |--A. castaneusLC40 [=Scaphidium (Agyrtes) castaneumG20; incl. Mycetophagus spinipesLC40]
| |--A. longulus (LeConte 1859) [=Necrophilus longulus]MP79
| `--A. similis Fall 1937MP79
`--Pterolomatinae [Pterolomini]P01
|--Pteroloma Gyllenhal 1827 [incl. Adolus Fischer 1828, Holocnemis Schilling 1829]P01
| `--P. nebrioides Brown 1933P01
`--Apteroloma Hatch 1927LC20, P90 (see below for synonymy)
|--A. arizonicumP90
|--A. caraboides (Fall 1907) [=Pteroloma caraboides]MP79
|--A. davidisR01
|--A. neelumenseR01
|--A. potaniniR01
|--A. qinlingense de Rougemont 2001R01
|--A. rostiR01
|--A. tahoecum (Fall 1927) [=Pteroloma tahoeca, P. (Apteroloma) tahoeca]MP79
`--A. tenuicorne (LeConte 1859) [=Necrophilus tenuicornis, Pteroloma (Apteroloma) tenuicorne]MP79
Apteroloma Hatch 1927LC20, P90 [incl. Alloloma Semenov-Tian-Shanskij 1932P01, Garytes Mroczkowski 1966P01, Pterolorica Hlisnikovsky 1968P01]
Ipelates Reitter 1884MW15, P90 [incl. Brachyloma Portevin 1914 non Chambers 1878P01, Necrophilodes Champion 1933P01, Necrophiloides (l. c.)P01, Pelates Horn 1888 non Cuvier & Valenciennes 1829P01, Pelatines Cockerell 1906P01, Sphaeroloma Portevin 1905P01]
Necrophilus Latreille 1829MW15, P90 [incl. Necrobius Gistel 1834P01, Paranecrophilus Shibata 1969P01, Pseudosilpha Schawaller 1978P01]
*Type species of generic name indicated
References
[B14] Bouchard, P. (ed.) 2014. The Book of Beetles: A lifesize guide to six hundred of nature’s gems. Ivy Press: Lewes (United Kingdom).
[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.
[GN09] Grebennikov, V. V., & A. F. Newton. 2009. Good-bye Scydmaenidae, or why the ant-like stone beetles should become megadiverse Staphylinidae sensu latissimo (Coleoptera). European Journal of Entomology 106: 275–301.
[LC40] Laporte de Castelnau, F. 1840. Histoire Naturelle des Insectes Coléoptères vol. 2. P. Duménil: Paris.
[LC20] Lü, L., C.-Y. Cai, X. Zhang, A. F. Newton, M. K. Thayer & H.-Z. Zhou. 2020. Linking evolutionary mode to palaeoclimate change reveals rapid radiations of staphylinoid beetles in low-energy conditions. Current Zoology 66 (4): 435–444.
[MF15] McKenna, D. D., B. D. Farrell, M. S. Caterino, C. W. Farnum, D. C. Hawks, D. R. Maddison, A. E. Seago, A. E. Z. Short, A. F. Newton & M. K. Thayer. 2015. Phylogeny and evolution of Staphyliniformia and Scarabaeiformia: forest litter as a stepping stone for diversification of nonphytophagous beetles. Systematic Entomology 40: 35–60.
[MW15] McKenna, D. D., A. L. Wild, K. Kanda, C. L. Bellamy, R. G. Beutel, M. S. Caterino, C. W. Farnum, D. C. Hawks, M. A. Ivie, M. L. Jameson, R. A. B. Leschen, A. E. Marvaldi, J. V. McHugh, A. F. Newton, J. A. Robertson, M. K. Thayer, M. F. Whiting, J. F. Lawrence, A. Ślipiński, D. R. Maddison & B. D. Farrell. 2015. The beetle tree of life reveals that Coleoptera survived end-Permian mass extinction to diversify during the Cretaceous terrestrial revolution. Systematic Entomology 40 (4): 835–880.
[MP79] Miller, S. E., & S. B. Peck. 1979. Fossil carrion beetles of Pleistocene California asphalt deposits, with a synopsis of Holocene California Silphidae (Insecta: Coleoptera: Silphidae). Transactions of the San Diego Society of Natural History 19 (8): 85–106.
[P90] Peck, S. B. 1990. Insecta: Coleoptera Silphidae and the associated families Agyrtidae and Leiodidae. In: Dindal, D. L. (ed.) Soil Biology Guide pp. 1113–1136. John Wiley & Sones: New York.
[P01] Peck, S. B. 2001. Agyrtidae C.G. Thomson, 1859. In: Arnett, R. H., Jr & M. C. Thomas (eds) American Beetles vol. 1. Archostemata, Myxophaga, Adephaga, Polyphaga: Staphyliniformia pp. 247–249. CRC Press: Boca Raton.
[R60] Richards, A. M. 1960. Observations on the New Zealand glow-worm Arachnocampa luminosa (Skuse) 1890. Transactions of the Royal Society of New Zealand 88 (3): 559–574.
[R01] Rougemont, G. M. de. 2001. Description of a new species of Apteroloma from China (Coleoptera, Agyrtidae). Revue Suisse de Zoologie 108 (2): 351–353.