Volumes & issues:
21, 1(2017); http://dx.doi.org/10.2517/2016PR015View Description Hide DescriptionAbstract.
Echinoid bite traces on Late Cretaceous (early Maastrichtian) bourgueticrinids and isocrinids of southern Poland (Miechów Trough) were documented. The bitten sea lilies co-occurred with Goniopygus, a regular echinoid possessing an Aristotle's lantern. This is the first record of Goniopygus in the lower Maastrichtian of Poland. Considering former studies, as well as direct in situ observations of extant sea lilies and sea urchin behavior, the traces at hand could be most likely linked with predatory actions of the Goniopygus echinoid. Such studies on predatory phenomena are crucial and could provide baseline data concerning the evolutionary trends among organisms engaged in the “arms race”.
Marine Palynomorphs Dominated by Heterotrophic Organism Remains in the Tropical Coastal Shallow-Water Sediment; the Case of Selangor Coast and the Estuary of the Manjung River in Malaysia21, 1(2017); http://dx.doi.org/10.2517/2016PR006View Description Hide DescriptionAbstract.
We aimed to clarify and quantify the abundance of palynomorphs of tropical coastal marine shallow-water sediments collected from Oman, Malaysia, Okinawa and also the Sanriku region of Japan for making a comparison with temperate areas. Palynomorphs in these samples contained phototrophic and heterotrophic dinoflagellate cysts, acritarchs, resting cells of Prasinophyceae and Chrysophyceae, tintinnomorphs, microforaminiferal linings, testate amoebae and resting eggs and body fragments of copepods. The sediment samples from Malaysia, Oman, and Okinawa were characterized by dominance of heterotrophic marine palynomorphs, in particular microforaminiferal linings and heterotrophic dinoflagellate cysts, while the samples from Sanriku were different and dominated by phototrophic and heterotrophic dinoflagellate cysts. In addition subtropical-tropical assemblages were characterized by low cell/grain concentrations, especially phototrophic dinoflagellate cysts. These characteristics of marine palynomorphs in tropical shallow-water sediments may reflect lower production of phytoplankton in water column as well as high sedimentation rates. Also, high densities of heterotrophic palynomorphs consisting of microforaminiferal linings, tintinnomorphs, crustacean remains and other elements are other characteristics for tropical coastal shallow-water marine sediments. It is difficult to explain the abundant occurrences of heterotrophic dinoflagellate cysts based on the grazing food web against the fact of low phytoplankton production.
How Striations of Ophiuroid and Asteroid Trace Fossils were Produced—Observations of Tube-Feet Movement in Living Ophiuroids and Asteroids21, 1(2017); http://dx.doi.org/10.2517/2016PR003View Description Hide DescriptionAbstract.
To clarify the process of producing the striations in the trace fossil Asteriacites, we observed the behavior of living ophiuroids and asteroids in aquariums. When ophiuroids stopped crawling, they buried themselves shallowly in the substratum, removing substratum under their arms and discs by using their tube-feet. The basal-arm tube-feet produce well spaced, fine, parallel striations that are perpendicular to the arm axis. The oral tube-feet produce fine, radial striations in the central depression. When the ophiuroids resumed crawling, they raised their disc and four arms above the substratum and dragged one arm backward. The one backward arm erased the striations, and parallel fine striations remained in four arm depressions. Similarly, asteroids also produced wide and shallow striations perpendicular to the arm axis by tube-feet movement. When the asteroids started to move again, they bulldozed the substratum under the one preceding arm, where the striations were erased. Since the asteroids crawled raising the other four arms by their tube feet which produced rough and deep striations, the wide and shallow striations remained only in a half of each arm depression. The striations of Asteriacites lumbricalis and A. quinquefolius were similar in shape to the striations produced by movement of tube feet of living ophiuroids and asteroids, respectively.
Discovery of the Early Spathian (Late Olenekian, Early Triassic) Ammonoid Tirolites in the Hiraiso Formation, South Kitakami Belt, Northeast Japan21, 1(2017); http://dx.doi.org/10.2517/2016PR017View Description Hide DescriptionAbstract.
Until now, the Hiraiso Formation was considered to be entirely of Smithian (early Olenekian, Early Triassic) age, but the discovery of the ammonoid Tirolites cf. ussuriensis in the lower part of the formation on the rocky coast between the Maekawara and Akaushi ports, Motoyoshi Town, Kesennuma City, in the South Kitakami Belt, Northeast Japan, establishes that this portion is actually equivalent to the upper part of the lower Spathian Tirolites-Amphistephanus Zone (upper Olenekian). The fauna of the Hiraiso Formation, which includes the large bivalve Eumorphotis iwanowi and crinoid ossicles, very much resembles the Tirolites ussuriensis beds in South Primorye, Russian Far East, suggesting a wide distribution of this shallow marine fauna in the low to middle northern latitudes on the western side of the Panthalassa during the early Spathian. Because pre-Spathian deposits contain only small-sized species of Eumorphotis and very rare crinoid ossicles, the appearance of large species of Eumorphotis and the flourishing of crinoids in the shallow marine environment during the early Spathian suggest that the Smithian-Spathian boundary marks a major change in the marine ecosystem.
First Record of a New Species of Amblypygus (Echinoidea) from the Middle Miocene of Mersa Matruh, Western Desert, Egypt21, 1(2017); http://dx.doi.org/10.2517/2016PR016View Description Hide DescriptionAbstract.
The echinoid genus Amblypygus Agassiz is reported for the first time from the middle Miocene and is represented by a new species, A. matruhensis sp. nov., from the area west of Mersa Matruh, Western Desert, Egypt. This extends the range of Amblypygus from the lower Eocene to the middle Miocene. A morphological comparison between the two genera Amblypygus and Echinoneus shows that they differ in that Amblypygus has a semi-ethmolytic apical disc and crenulate, perforate tubercles whereas Echinoneus has an ethmophract apical disc and non-crenulate, non-perforate tubercles. The paleoecology and the paleogeography of the genus Amblypygus are discussed.
Taxonomy of Maastrichtian—Thanetian Deep-Sea Ostracodes from U1407, IODP Exp 342, Off Newfoundland, Northwestern Atlantic, Part 1: Families Cytherellidae, Bairdiidae, Pontocyprididae, Bythocytheridae, and Cytheruridae21, 1(2017); http://dx.doi.org/10.2517/2016PR010View Description Hide DescriptionAbstract.
In ocean drilling sites, the taxonomy of Paleocene ostracodes has been poorly investigated. We describe and illustrate 18 ostracode taxa from Cretaceous—Paleocene sediments at U1407 of Integrated Ocean Drilling Program Expedition 342 off Newfoundland, Northwestern Atlantic; these 18 taxa belong to the families Cytherellidae, Bairdiidae, Pontocyprididae, Bythocytheridae, and Cytheruridae, and include five new species: Bythoceratina subumbonata sp. nov., Bythoceratina wilsoni sp. nov., Cytheropteron newfoundlandense sp. nov., Cytheropteron americanum sp. nov., and Nemoceratina (Pariceratina) guerneti sp. nov. Our identification and description of the taxa enable us to assess paleobiodiversity and paleoenvironments on the seafloor in the North Atlantic.
21, 1(2017); http://dx.doi.org/10.2517/050.021.0101View Description Hide Description
Correction to the paper by Yuichiro Nishioka, Ren Hirayama, Shigenori Kawano and Shinkai Ogino, 2016: Lower Miocene cervoid ruminants (Artiodactyla) from the Koura Formation, Matsue, southwestern Japan. Paleontological Research, vol. 20, no. 4, pp. 289–295.
In Table 1 on page 292, “Dicrocerus tokunagai”, “Dicrocerus grangeri”, “Amphitragulus minoensis” and “Sinomeryx tricornis” should be italicized.
21, 1(2017); http://dx.doi.org/10.2517/2016PR014View Description Hide DescriptionAbstract.
This study describes a new genus of melocrinitid crinoid from the Middle Devonian, Givetian Stage, of Iowa (subclass Camerata, family Melocrinitidae). The specimen described is assigned to Ronsocrinus gen. nov. within the family Melocrinitidae. Ronsocrinus rabia gen. et sp. nov. possesses a long heteromorphic column, small calyx plates with raised stellate patterns and a well-developed, long anal tube. Species within the family Melocrinitidae do not commonly possess a long anal tube or a spherical cup shape and the family diagnosis is expanded to include species with these characteristics.
21, 1(2017); http://dx.doi.org/10.2517/2016PR008View Description Hide DescriptionAbstract.
All species of the genus Sinamia (Sinamiidae, Amiiformes) are reviewed on the basis of the examination of the holotypes, paratypes, other specimens, and original descriptions of each species. Diagnoses are provided for all species. Phylogenetic analysis supports the monophyly of the family Sinamiidae and demonstrates that the long dorsal fin base in Sinamia and Amia is a matter of convergence. It is considered that the species having a long dorsal fin base lived in still water with vegetation, like Amia calva, while the species having a short dorsal fin base probably lived in the open water.
20, 4(2016); http://dx.doi.org/10.2517/2015PR037View Description Hide DescriptionAbstract.
Dental fossils of an indeterminate small cervoid (Ruminantia, Artiodactyla, Mammalia) from the lower Miocene Koura Formation of southwestern Japan are described. The examined specimens of Cervoidea fam., gen. et sp. indet. consist of selenodont lower molars with plesiomorphic characteristics of early cervoids: a strong external postprotocristid (or Palaeomeryx-fold), a deep groove on the lingual wall of the internal postmetacristid, and opening posterior cristids between the postentocristid and the posthypocristid. The lower molars are similar in shape and size with those of Miocene Cervidae rather than Moschidae or Palaeomerycidae because the present specimens are comparable to those of Dicrocerus tokunagai, which is one of the lower/ middle Miocene cervids from northeastern Japan, and D. grangeri from the middle Miocene of China. The lower Miocene Nakamura Formation (ca. 19 Ma) of central Japan also yielded a small cervoid species sharing the lower molar characteristics with Cervoidea fam., gen. et sp. indet. from the Koura Formation, suggesting a faunal or biostratigraphical correlation between the two formations.