Megaphyllum unilineatum, copyright Zdeněk Hyan.Belongs within: Eugnatha. Contains: Cylindroiulus, Leptoiulus, Julus. The Julida are a group of millipedes with pleura fused with terga, and a gnathochilarium with meeting stipes. Members of the families Paeromopodidae and Julidae bear distinct, fine longitudinal striation all around the metazonal segments; members of other families have such striation absent or… Continue reading Julida

A Second Look at Scallops

In a post that appeared at this site over eight years ago, I described some of the distinctive features of the Pectinoidea, the group of bivalves commonly known as scallops. It’s time to look in a bit more detail at some of the points mentioned in that post. Fossil of Pernopecten, the earliest scallop genus,… Continue reading A Second Look at Scallops


Yellow flat-backed millipedeCherokia georgiana, copyright Sheryl Pollock. Belongs within: Polydesmida. The Xystodesmoidea are a group of millipedes with usually prominent paraterga and bodies incapable of rolling into a ball. Characters (from Enghoff et al. 2015): Length ca. 8 to more than 80 mm, exceptionally smaller. Body not capable of volvation, broad and robust, width/length ratio… Continue reading Xystodesmoidea

Pontodrilus: Earthworms by Sea

Earthworms are primarily a terrestrial and freshwater group, sensitive to changes in the quality of their habitat. But there are some earthworm species that are tolerant of more saline environments. One such species is Pontodrilus litoralis, a widespread earthworm found in warm coastal habitats around the world, being recorded from such far-flung places as the… Continue reading Pontodrilus: Earthworms by Sea


Belongs within: Pectinida. Deltopecten is a genus of scallops known from the Late Permian of Australia (Cox et al. 1969). Characters (from Cox et al. 1969): Large, orbicular, radially plicate shells with or without fine costae; ligament area striated more or less parallel to hinge axis, resilifers lacking. <==Deltopecten Etheridge 1892DX84 |–D. clarkei Fletcher 1929F71… Continue reading Deltopecten


Belongs within: Enoplia. The Diphtherophorina are a group of plant-parasitic nematodes whose head bears a protrusible piercing spear (Ley & Blaxter 2002). Diphtherophorina [Diphtherophoroidea] |–DiphtherophoridaeLB02 `–TrichodoridaeLB02 |–ParatrichodorusW02 | |–P. allius [=Trichodorus allius]W02 | `–P. porosus [=Trichodorus porosus]W02 `–Trichodorus Cobb 1913MW69 |–T. borneoensisJ02 |–T. californicusJ02 |–T. cedarusJ02 |–T. coomansiJ02 |–T. cottieriJ02 |–T. cylindricusJ02 |–T. dilatatusJ02 |–T.… Continue reading Diphtherophorina


Belongs within: Orthoceratia. The Lower to Middle Ordovician Baltoceratidae were a family of relatively large orthoconic early cephalopods. Characters (from Furnish & Glenister 1964): Smooth, longiconic orthocones with moderately large marginal siphuncle, orthochoanitic septal necks and thin homogenous connecting rings. Baltoceratidae [Cochlioceratidae]K93 |–Murrayoceras Foerste 1926FG64 | `–*M. murrayi (Billings 1857) [=Orthoceras murrayi]FG64 |–Ogygoceras Ulrich, Foerste… Continue reading Baltoceratidae


Belongs within: Pseudorthoceratidae. Spyroceras is a Devonian genus of orthocerid cephalopod recorded from Europe and North America. Characters (from Sweet 1964): Annulated orthocones with straight transverse sutures, transverse or slightly oblique surface annulations, and faintly cyrtoconic apices. Surface variously ornamented, longitudinal lirae conspicuous from earliest stage. Siphuncle central or slightly ventral; siphuncle orthochoanitic with forward-growing… Continue reading Spyroceras


Belongs within: Orthoceratia. The Troedssonellidae were a Lower to Middle Ordovician family of orthocerid cephalopods that formed endocones in the apical part of their siphuncles. Characters (from Sweet 1964): Siphuncle suborthochoanitic; continual endosiphuncular lining of parietal deposits prolonged adapically to form endocones. Troedssonellidae [Buttsoceratidae, Troedssonellina]S64 |–Tajaroceras wardae Hook & Flower 1976K93 |–Moridunoceras Evans 2005KE19 |–Oxfordoceras… Continue reading Troedssonellidae