New record of the swimming crab Charybdis (Archias) hongkongensis Shen, 1934 (Brachyura, Portunidae) from India

Charybdis (Archias) hongkongensis Shen, 1934 was collected from the Indian coast of the Bay of Bengal and this is the first record from Indian waters. The distinct key characters of this species are: a relatively more produced last antero-lateral tooth, strongly convergent postero-lateral margins, and a smooth, rounded, reduced apex of the male first gonopod. This is the ninth member of Charybdis (Archias) Alcock, 1899 from Indian waters. The species is diagnosed and figured herein.

Examination of the stresses of the implants applied to the atrophic edentulous maxilla on the maxillary bone

Aim: In advanced atrophy of the posterior maxilla, applied zygoma implants increase the success of the surgical procedure by reducing morbidity and procedure time. In our study, using tomographic records, a model with posterior atrophy was obtained in a computer environment, and zygomatic and dental implants in different numbers and localizations were applied to this model. The aim of our study was to choose the most accurate surgical planning according to the stresses arising from the applied forces. Methodology: In our study, one zygoma implant on the right and left in Group 1, two zygoma implants in Group 2, one zygoma implant in Group 3 and one dental implant in the first premolar tooth area, one zygoma implant in Group 4 and one dental implant in the lateral tooth area and one zygoma implant in Group 5 and one dental implant in the lateral and a first premolar tooth area were applied. 150 N were applied vertically to the prosthetic superstructure from the lateral tooth, 1st premolar tooth, 1st molar tooth and 2nd molar tooth. As a result of the applied forces, the maximum stress values ​​in the maxilla molar region were examined by finite element stress analysis. Results: In our study, it was observed that Group 1 had the highest stress value, followed by Group 3. Stress values in Groups 2, 4 and 5 were low and they were measured close to each other. Conclusion: As a result of our study, it was seen that zygomatic and dental implants applied in addition to the zygomatic implant reduce stress and the localization of dental implants affect the stress values. How to cite this article: Gülsün B, Çetindağ A. Examination of the stresses of the implants applied to the atrophic edentulous maxilla on the maxillary bone. Int Dent Res 2021;11(Suppl.1):210-5. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.30 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

A TOOTH OF THE EXTINCT LAMNID SHARK, COSMOPOLITODUS PLANUS COMB. NOV. (CHONDRICHTHYES: ELASMOBRANCHII) FROM THE MIOCENE OF POHANG CITY, SOUTH KOREA

An isolated, upper lateral tooth of the extinct lamnid shark Cosmopolitodus planus (Agassiz, 1856), is described from middle Miocene marine deposits (possibly the Duho Formation) in Pohang City, South Korea. This is the first confirmed record of this taxon in the Korean Peninsula. The tooth is less than half the size of a large tooth of this species, suggesting that the tooth comes either from an intermediate or posterior position within the upper jaw, or from a young individual. This report further supports the hypothesis that epipelagic or pelagic sharks were already distributed throughout the entire East Sea in the middle Miocene. It is recommended that the species planus should be transferred to the genus Cosmopolitodus based on numerous similarities with the type species of this genus, C. hastalis (Agassiz, 1838).

Are the ICZN and PhyloCode that incompatible? A summary of the shifts in Stromboidean taxonomy and the definition of two new subfamilies in Stromboidae (Mollusca, Neostromboidae)

The taxonomy of Stromboideans has, historically, been simplistic. However, recent revisions have seen new taxa introduced to distinguish relationships between species clusters. We discuss these numerous advancements in Stromboidean systematics, and describe two new subfamilies here. The key diagnostic characteristic, the basal peg on the first lateral tooth, splits the Strombidae into two clades similar to those observed with molecular data. In defining the new subfamilies, Neoaligerinae and Neostrombinae, we demonstrate that the practical application of the International Code of Phylogenetic Nomenclature (PhyloCode 2020), can also conform to the requirements of the International Code of Zoological Nomenclature (ICZN 1999). This revision further advances and strengthens the framework of Stromboidean nomenclature such that it is able to reflect the current understanding of the evolutionary relationships between members of the Stromboidea.

Epimeria cleo sp. nov., a new crested amphipod from the Ross Sea, Antarctica, with notes on its phylogenetic affinities (Crustacea, Amphipoda, Eusiroidea, Epimeriidae)

A new crested amphipod, Epimeria cleo sp. nov., is described after specimens collected in the western Ross Sea, Southern Ocean, at 151–409 m depth. This increases the number of Epimeria species known from the Ross Sea to eleven. This new species belongs to the subgenus Drakepimeria d'Udekem d'Acoz & Verheye, 2017. E. cleo sp. nov. has very robust walking pereiopods, no mid-dorsal tooth or bump on pereonites 1–2, no lateral tooth or angle on the lateral carina of coxa 4 and no pair of small teeth pointing upwards on urosomite 2. It is morphologically very similar to Epimeria leukhoplites d'Udekem d'Acoz & Verheye, 2017, E. reoproi Lörz & Coleman, 2001 and E. vaderi Coleman, 1998, the latter three species being known only from the Antarctic Peninsula and South Shetland Islands. Epimeria cleo sp. nov. can be distinguished from them by the following combination of characters: flexed rostrum, narrow coxa 3, long ventral tooth on coxa 4 and non-duplicate lateral tooth on pleonites 1–2. The phylogenetic relationships between E. cleo sp. nov. and other Epimeria of the subgenus Drakepimeria, for which DNA sequences are available, are briefly outlined based on a phylogenetic analysis of 28S rDNA fragments.

Deep-sea chitons of the genus Stenosemus (Mollusca: Polyplacophora) from Fiji and Solomon Islands

Three new species of the genus Stenosemus collected near Fiji and Solomon Islands of the central Pacific are described here. Stenosemus fijiensis sp. nov. from Fiji differs from the congeneric species by a unique sculpture of the central areas of tegmentum, consisting of triangular pits and light brown spots on valves. S. philippei sp. nov. and S. solomonensis sp. nov., both from the Solomon Islands, differ from other the species of the genus by having a head of major lateral tooth of radula bicuspidate with small outer denticle, shape and sculpture of dorsal spicules and sculpture of tegmentum.

Three new species of freshwater crabs of the genus Pseudothelphusa (De Saussure, 1857) (Crustacea: Decapoda: Pseudothelphusidae) from Mexico

Three new species of freshwater crabs of the genus Pseudothelphusa (De Saussure, 1857) from south-central Mexico are described: Pseudothelphusa acahuizotla n. sp., P. ixtapan n. sp., and P. purhepecha n. sp. The new species are included in Pseudothelphusa due to a male gonopod with torsion and the presence of the characteristic mesial process and caudomarginal projection. Pseudothelphusa acahuizotla n. sp. is morphologically similar to P. belliana Rathbun, 1898, but can be distinguished by the relative size of the distal lobe of the caudomarginal projection and by the presence of a conical tooth on the caudal surface of the mesial process of the male gonopod. Pseudothelphusa ixtapan n. sp. is similar to P. dilatata Rathbun, 1898, and P. morelosis Pretzmann, 1968, and can be distinguished by a mesial process of the male gonopod with only one lateral tooth and an inferior margin with small teeth. Pseudothelphusa puerhepechae n. sp. exhibits a mesial process of the male gonopod with two triangular spines on its lateral margin, a character that with some variations is present in P. nayaritae Álvarez & Villalobos, 1994, P. rechingeri Pretzmann, 1965, P. lophophallus Rodríguez & Smalley, 1969, and P. parabelliana Álvarez 1989; but it can be distinguished by the separation and shape of the two spines of the mesial process and the shape of the lobes of the caudomarginal projection. With the new species described herein there are now 29 species in the genus Pseudothelphusa.