Tentorium

Beutel Dominique Zimmermann Marcus Krauss Susanne Randolf Benjamin Wipfler, Rolf G., 2010, Head morphology of Osmylus fulvicephalus (Osmylidae, Neuroptera) and its phylogenetic implications, Organisms Diversity & Evolution (New York, N. Y.) 10 (4), pp. 311-329 : 315

Tentorium ( Figs. 3a–d ; 4a ; 6a, b ; 8b, c ; 9a )

The tentorium is fully sclerotised. It connects the large anterior tentorial pits at the posterolateral clypeal margin with the posterior tentorial pits at the foramen magnum. The tentorial bridge ( Figs. 4a ; 6b ; 9a : tb) connects the well developed posterior arms ( Figs. 3b ; 4a : pta). The anterior arms ( Figs. 3a–d ; 4a ; 6a, b ; 8b, c : ata) diverge slightly, and the dorsal arms ( Figs. 3c ; 4a ; 6a, b : dta) originate at about midlength. They are attached to the head capsule by fibrillae. The anterior arms are strongly developed, approximately round in cross section, and hollow, like the posterior arms. They widen towards the anterior pits and form a shovel-like extension serving as a muscle attachment area.

Figures

Fig. 3 Osmylus fulvicephalus, head, three-dimensional reconstructions. a Frontal view, including right half of head capsule. b Lateral view of brain, tracheae and selected muscles. c Anterolateral view of brain, tentorium and selected muscles. d Anterolateral (nearly lateral) view of brain and selected muscles. Labels: ata=anterior tentorial arm, dcer=deuterocerebrum, dta=dorsal tentorial arm, fcon=frontal connective, fg=ganglion frontale, nan=antennal nerve (right antennal nerve obliterated in specimen used for microtome sectioning), ncon= nervus connectivus, noc=ocellar nerve (median ocellar nerve obliterated in specimen used for microtome sectioning), nrec=nervus

Fig. 4 Osmylus fulvicephalus, three-dimensional reconstruc- tions. a Tentorium. b Left man- dible. c Mandibles in situ. Labels: ata=anterior tentorial arm, dta= dorsal tentorial arm, pta=posterior tentorial arm, tb= tentorial bridge, 11=M. cranio- mandibularis internus, 12=M. craniomandibularis externus

Fig. 6 Osmylus fulvicephalus, maxilla, three-dimensional reconstruction. a Lateral view. b Frontal view. Labels: ata=anterior tentorial arm, ca=cardo, dta=dorsal tentorial arm, ga=galea, lac=lacinia, mxp= maxillary palp, sti=stipes, tb=tentorial bridge, 15=M. craniocardinalis externus, 17=M. tentoriocardinalis, 18=M. tentoriostipitalis, 19= M. craniolacinialis, 20=M. stipitolacinialis, 21=M. stipitogalealis, 22=M. stipitopalpalis externus, 23=M. stipitopalpalis internus, 24= M. palpopalpalis maxillae primus

Fig. 8 Osmylus fulvicephalus, head, cross sections. a Level of ganglion frontale. b Level of compound eye. c Level of brain. Labels: alb=anterior labium, ata=anterior tentorial arm, cl=clypeus, con= condyle (primary joint), dcer=deuterocerebrum, md=mandible, mdg= mandibular gland, noc=ocellar nerve, oc = ocellus, onp=optic neuropils, pcer=protocerebrum, ph=pharynx, sc=scapus, smj=secondary mandibular joint, soeg=suboesophageal ganglion, 1=M. tentorioscapalis anterior, 2=M. tentorioscapalis posterior, 6 = M. scapopedicellaris medialis, 9 =M. frontoepipharyngalis, 12 =M. craniomandibularis externus, 17=M. tentoriocardinalis, 18=M. tentoriostipitalis, 23=M. stipitopalpalis internus, 29=M. tentoriopraementalis inferior, 34= praementopalpalis externus, 41a, b=M. frontohypopharyngalis, 44= M. clypeobuccalis, 46=M. frontobuccalis posterior, 67=M. transversalis buccae

Fig. 9 Osmylus fulvicephalus, head, cross sections. a Level of subosephageal ganglion. b Level of posterior labium. c Level of cervix. Labels: oes=oesophagus, ph=pharynx, soeg=suboesophageal ganglion, tb=tentorial bridge, tr=tracheae, 11=M. craniomandibularis internus, 12=M. craniomandibularis externus, 17=M. tentoriocardinalis, 18=M. tentoriostipitalis, 20=M. stipitolacinialis, 28=M. submentopraementalis, 29=M. tentoriopraementalis inferior, 42 =M. tentoriohypopharyngalis, 51=M. verticopharyngalis