Part K, Mollusca 3, Complete Volume

Abstract

NAME CHANGES IN RELATION TO GROUP CATEGORIES SPECIFIC AND SUBSPECIFIC NAMESDetailed consideration of valid emendation of specific and subspecific names is unnecessary here because it is well underxu

Ammonoid Buccal Mass and Jaw Apparatus

“…10.10a), whereas the calcified tip of the upper jaw and the outer calcareous layer of the lower jaw in Hypophylloceras are both made of calcite . The anterior calcareous tips of the rhynchaptychus-type jaws fairly resemble in shape and internal microstructure not only those of modern and fossil nautilid jaws but also of the isolated arrowhead-and scallop-shaped calcareous remains called rhyncholites and conchorhynchs that have been found from the Late Paleozoic and younger marine deposits (Teichert et al 1964;Teichert and Spinosa 1971;Riegraf and Luterbacher 1989). This fact suggests that at least some previously known Jurassic and Creta-ceous counterparts belonged to either Lytoceratina or Phylloceratina (Tanabe et al 1980aTanabe and Fukuda 1999).…”

Non-destructive, safe removal of conductive metal coatings from fossils: a new solution

“…They have been found from the Late Paleozoic and younger marine deposits, and some of them from the Jurassic and Cretaceous are interpreted to be the calcified deposits of the upper and lower jaws of either lytoceratid or phylloceratid ammonoids (see review by Tanabe et al, 2015). The overall morphology of the calcareous covering of the lower jaw of the examined P. ezoensis could be comparable to other known conchorhynchs (e.g., Teichert et al, 1964;Saunders et al, 1978) and conchorhynch-like structures of Lytoceratina (Tanabe et al, 1980;Kanie, 1982) and Phylloceratina (Tanabe and Landman, 2002;Tanabe et al, 2013). However, that of the upper jaw of P. ezoensis is quite different from other known rhyncholites.…”

“…However, that of the upper jaw of P. ezoensis is quite different from other known rhyncholites. Although the absence of a mid-dorsal projection from the anterior calcareous portions in the examined specimen is a characteristic of Rhynchotuethis, a morphotype of rhyncholites (e.g., Teichert et al, 1964;Teichert and Spinosa, 1971;Riegraf and Luterbacher, 1989;Nemoto and Tanabe, 2008;Riegraf and Moosleitner, 2010), a shaft-like prolongation that extends into the concave interior of the upper jaw, which is the general characteristic of the known rhyncholites (Teichert et al, 1964), is absent in P. ezoensis. Such specific feature of the calcareous deposits on P. ezoensis upper jaw might be as a result of ecological-functional constraints (as discussed later).…”

“…Arrowhead-and scallop-shaped calcareous coverings of organisms are called rhyncholites and conchorhynchs, respectively (Teichert et al, 1964). They have been found from the Late Paleozoic and younger marine deposits, and some of them from the Jurassic and Cretaceous are interpreted to be the calcified deposits of the upper and lower jaws of either lytoceratid or phylloceratid ammonoids (see review by Tanabe et al, 2015).…”

Postmortem transport in fossil and modern shelled cephalopods

“…Geographic range was estimated as the log 10 of the area in square kilometers of a convex hull encompassing all occurrences of each taxon; see Yacobucci (2017) for further details. To determine the position of these genera in Westermann Morphospace, images of specimens of each genus were located in the ammonoid Treatise volumes ( Arkell et al, 1957 ; Wright, Callomon & Howarth, 1996 ) and the nautiloid Treatise volume ( Teichert et al, 1964 ) for Eutrephoceras . These images were used to measure the necessary shell shape characters.…”