NEWSLETTER 12/2023 21.12.2023

NEW PARTNERS OF SHARK-REFERENCES

Would you like to become a shark-reference partner? Please contact us per E-mail!

NEW SECTION: From now on, we will report last month’s most popular three papers from our Shark References Facebook page:

Nr. 1 (101 Likes/Emojis, 55 Shares):

Here, we focus on the elasmobranch fauna to determine the trophic relationships within the OMM, using fossil teeth as proxies for diet and trophic levels based on functional morphology and an actualistic species- or genus-level approach. Herein we present a fresh and comprehensive palaeoecological reconstruction of the OMM ecosystem in Baden-Württemberg. All five outcrop areas available for the present analysis (Baltringen, Meßkirch-Rengetsweiler, Meßkirch-Walbertsweiler, Ulm-Ermingen, and Ursendorf) exhibit a similar faunal composition, with the apex predator being Otodus (Megaselachus) sp. Among the other elasmobranchs, there are mostly piscivorous and malacophagous species; taxa that feed on a variety of other invertebrates or amniotes (including marine mammals) are also present. The OMM sediments deposited in shallow-water settings, but there are fossils of more oceanic species that might, at times, have approached the shore. With a soft bottom, partly covered by sea grass, the OMM environment would have been like the present-day warm-waters settings of the Mediterranean.

Höltke, Olaf, Salvador, Rodrigo B., and Rasser, Michael W. 2023. Trophic relationships in the Early Miocene Upper Marine Molasse of Baden-Württemberg, Southwest Germany, with special emphasis on the elasmobranch fauna. Palaeontologia Electronica, 26(3):a46.
https://doi.org/10.26879/1233
http://palaeo-electronica.org/.../4000-trophic-relationships


Nr. 2 (99 Likes/Emojis, 51 Shares):

Gymnurid rays are found in tropical, subtropical, and temperate regions around the world, where they are associated with sandy or muddy bottoms in coastal areas, being easily distinguished from other rays by the width of the disc. In recent years, the systematics of this family have been revised extensively. However, there has been no comprehensive molecular review of the family based on an adequate sample of species and localities, which may have obscured the presence of distinct evolutionary lineages. The present study was based on samples of 12 of the 13 valid species of the genus Gymnura, which were used for a multilocus reconstruction of the evolutionary history of the family Gymnuridae. Our results indicate the existence of several cryptic gymnurid lineages, within the species Gymnura micrura, Gymnura lessae, Gymnura altavela, and Gymnura poecilura. Also, we indicate that only half of the species that compose the genus are known, as well their conservation status. The analyses also indicate that the gymnurids originated during the Paleocene, with events of dispersal and vicariance occurring through the formation of oceanographic barriers, and species diversification peaking during the Oligocene and Miocene. The results of the present study reinforce the need for a comprehensive revision of the systematics of the family, in particular, the widely distributed species that are considered valid taxa, but may, in fact, represent different cryptic species. The inadequate classification of this cryptic diversity may have negative implications for the development of effective conservation measures.

Gales, S.M. & Parsons, K.T. & Biesack, E.E. & Ready, J. & Siccha-Ramirez, R. & Rosa, L.C. & Rosa, R. & Rotundo, M.M. & Bills, R. & Rodrigues, A.E.S. & Rodrigues-Filho, L.F.S. & McDowell, J. & Sales, J.B.L. 2023 Almost half of the Gymnura van Hasselt, 1823 species are unknown: Phylogeographic inference as scissors for cutting the hidden Gordian knot and clarify their conservation status. Journal of Systematics and Evolution, in press
https://onlinelibrary.wiley.com/doi/full/10.1111/jse.13027


Nr. 3 (66 Likes/Emojis, 9 Shares):

Many thanks to Allessandro De Maddalena for updating his sharks of the Maldives book:
This new 2023 edition includes an additional 3 species with respect to the 2017 edition, bringing the species included to 39.
DE MADDALENA, A. & P. GALLI (2023): Sharks of the Maldives. 2023 updated edition. Editoriale Magenes, Milano, 224 pp., color photographs and black and white drawings. ISBN: 9788866491576. Language: English.

New Images

Missing papers:

Many thanks to all friends of shark-references, who sent us some missing papers last month!

Shark-References would kindly like to ask you for your contribution to this project.

At the moment we are looking for some of the following papers:


Extinct Chondrichthyes:

new entry: Priem, R. (1920) Poissons fossils du Miocène d’Egypte. Burdigalien de Moghara, „Désert libyque“. In Fourtau: Contribution à l’étude des vertébrés miocènes de l’Egypte. Cairo 1920, pp. 8-15.

new entry: Arambourg, C. & Joleaud, L. (1943) Vertébrés fossiles du basin du Niger. Bulletin Direction des Mines, 7, 1–74

new entry:  Arambourg, C. (1954) Les Poissons Crétacés du Jebel Tselfat (Maroc). Notes et Mémoires du Service Géologique du Maroc, 118: 188 pp 18 Taf.

Numano, M. (1993) Some Neogene shark-teeth from Mogami area, Yamagata Prefecture. Applied Geology of Yamagata, 13: 32–49

new entry:  Schmitz, L. (2003) Fischzähne (Neoselachii; Actinopterygii) aus dem Unter-Barremium von NW-Deutschland. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 227, 175–199



Extant Chondrichthyes:

Chu, Y.-T.  (1930) A new species of the swallow ray (Pteroplatea) from China. China Journal, 12(6): 357

Smith, J.L.B. (1958) The mystery killer, the new shark Carcharhinus vanrooyeni. Veld & Vlei, 3 (9): 12–14, 28.

Deng, S.-M. & Xiong, G.-Q. & Zhan, H.-X. (1988) The deep water fishes of the east China Sea. Xue Lin Publishing house: 356 pp.

new entry: Barry, J.P. & Maher, N. (2000) Observations of the prickly shark, Echinorhinus cookei, from the oxygen minimum zone in Santa Barbara Basin, California. California Fish and Game, 86(3), 213–215



Please support www.shark-references.com and send missing papers (not listed papers or papers without the info-symbol) to juergen.pollerspoeck@shark-references.com or nicolas.straube@shark-references.com

Last, P.R. & Weigmann, S. & Naylor, G.J.P. (2023)

Extinct Chondrichthyes:
Boulemia, S. & Adnet, S. (2023) A new Palaeogene elasmobranch fauna (Tebessa region, eastern Algeria) and the importance of Algerian-Tunisian phosphates for the North African fossil record. Annales de Paléontologie, 109(3), Article 102632
New species: Physogaleus onkensis
Abstract: During the Palaeocene-Eocene transition, the southern Tethys margin is characterized by several African phosphate deposits with many fossil teeth of elasmobranchs. Contrary to the rich Moroccan fossil record, fossil elasmobranchs from the area that includes today the Algerian-Tunisian border (e.g. Metlaoui-Gafsa-Onk Basin) have received few attentation since the last century of exploration. New collecting in the vicinity of Tebessa, Eastern Algeria (Jebel El Onk mine) allowed to report a new elasmobranch fauna in the so-called “Upper Thanetian” level. It consists of 28 taxa including a new species of a galeocerdid, Physogaleus onkensis sp. nov., which is characterized by a possible crushing adaptability of their teeth. The majority of the reported species are known in coeval phosphate levels enabling preliminary conclusions about the depositional time and correlations to the related faunas of the region. The faunal from the Jebel El Onk mine is considered as late Thanetian–early Ypresian in age.


Parasites:
Palm, H.W. & Haseli, M. (2023) Tentaculariids (Cestoda, Trypanorhyncha) of elasmobranchs from Malaysian Borneo. Zoosystema, 45(18), 513–529
New species: Homeokotorella anterioporus, Nybelinia pseudafricana
Abstract: The waters off Borneo, the third-largest island in the world located at the geographic centre of Maritime Southeast Asia, harbour a high diversity of marine cestodes. We examined the tentaculariid species collection of the large-scale sampling endeavours in Malaysian Borneo between 2002 and 2008. Our study resulted in reporting the tentaculariid fauna of the region with greater detail, describing two new species, and erecting a new genus, Nybelinia pseudafricana n. sp. and Homeokotorella anterioporus n. gen., n. sp. A comparison of N. sphyrnae Yamaguti, 1952 from Malaysian Borneo, Australia, New Caledonia, and Japan revealed the synonymy of N. jayapaulazariahi Reimer, 1980 with N. sphyrnae. Remarks are provided for N. sphyrnae, N. aequidentata (Shipley & Hornell, 1906) Dollfus, 1930, Heteronybelinia estigmena (Dollfus, 1960) Palm, 1999, Tentacularia coryphaenae Bosc, 1802, Kotorella pronosoma (Stossich, 1900) Euzet & Radujkovic, 1989, and Kotorelliella (abbr. Ko.) jonesi Palm & Beveridge, 2002 and new host records are established for N. aequidentata and Ko. jonesi. Nybelinia aequidentata is reported for the first time from this region. Since most of the trypanorhynch species, including the tentaculariids, reported so far off Borneo are the same as those recorded off Indonesia, it seems that the trypanorhynch fauna of Borneo resembles the one from the Indonesian waters including to date 21 species (36%) of a total of 58 known tentaculariid species and 86 species (26%) of a total of 335 valid trypanorhynch species. These results allow us to better understand the species diversity of the tentaculariid trypanorhynchs off Malaysian Borneo.
 

PLEASE send your new papers to
juergen.pollerspoeck@shark-references.com or 
nicolas.straube@shark-references.com   

Latest Research Articles

MISCELLANEOUS:

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Beyond Jaws

In this episode of the Beyond Jaws podcast, we talk to Jaelyn Myers, a PhD student from Australia who started her graduate work during the COVID-19 pandemic. She shares the challenges she faced and discusses her science communication work with Stingrays. We also delve into the reasons behind her science communication efforts, her Instagram account, and the progress of her PhD.

Evolution of taste: Early sharks were able to perceive bitter substances

Date: November 13, 2023

Source: University of Cologne

Summary: New genetic data show that humans and sharks share bitter taste receptors, even though their evolutionary pathways separated nearly 500 million years ago.

Why a surprising discovery, warming seas and the demise of the 'Meg' may spell trouble for more and more sharks

Date: November 7, 2023

Source: Trinity College Dublin

Summary: Some unexpected shark strandings and subsequent surprises following autopsies have, ironically, taken marine biologists millions of years back in time as they look to the future with concern. Adding chapters to an evolutionary tale involving the infamous megalodon shark (the 'Meg'), they think their work suggests there are more warm-blooded sharks out there than previously believed, and -- based on the Meg's demise -- these species may be at great risk from warming seas.