Elsevier

Cretaceous Research

Volume 127, November 2021, 104949
Cretaceous Research

Short communication
Large-sized gladius-bearing octobrachians (coleoid cephalopods) in the Turonian plattenkalk of Vallecillo, Mexico

https://doi.org/10.1016/j.cretres.2021.104949Get rights and content

Abstract

The Turonian plattenkalk of Vallecillo (Mexico) yielded two large-sized gladiuses of octobrachian coleoids. The specimens determined as Boreopeltis ifrimae sp. nov. are both classified as members of the suborder Prototeuthina and represent the first coleoids from the Turonian of Mexico. Belemnoid coleoids are still unknown from Upper Cretaceous localities in Mexico. Boreopeltis ifrimae sp. nov. is the youngest representative of its genus. The occurrence of Boreopeltis in the northwestern Gulf of Mexico suggests a worldwide distribution in cold to warm temperate waters. The gladius (mantle) length of both specimens is remarkable and measures 470 mm, respectively. A general trend towards large and very large-sized coleoids is identified during the Late Cretaceous and began in the Turonian, as indicated by taxa from the southern Western Interior and the northern Gulf of Mexico. This gradual increase in octobrachian body sizes may reflect a commencing escalation in the arms race between coleoids, fishes, and marine reptilians.

Introduction

Cephalopods play a major role in extant marine food webs and inhabit a wide range of marine niches, from intertidal environments to deep oceanic trenches (see Vidal, 2014, Vidal, 2014 and literature therein). This importance must have been similar during most of the Phanerozoic, but fossil preservation of this fascinating group of mollusks, particularly of the mainly soft bodied endocochleates, or Coleoidea, is usually bad. Our paleobiological knowledge of coleoid cephalopods, with reduced calcareous (cuttlebone) or chitinous (gladius) internal support structures, or even “soft-bodied” forms, is therefore based on Konservat Lagerstätten sensu Seilacher (1970) favouring the preservation of soft tissue material, such as the lower Jurassic (Toarcian) Posidonia Shale of Central Europe (e.g., Fuchs, et al., 2013), the middle Jurassic (Callovian) of Christian Malford, UK, La Voulte-sur-Rhône, France (e.g., Fuchs, 2014; Kruta et al., 2016), the upper Jurassic (Kimmeridgian – Tithonian) Solnhofen and Nusplingen plattenkalks of Germany (e.g., Klug et al., 2005, 2015; Fuchs et al., 2007a, b), or the upper Cretaceous (Cenomanian–Santonian) plattenkalks of Lebanon (e.g., Fuchs et al., 2009; Fuchs and Larson, 2011a, b). The abundance of coleoid cephalopods in these localities is comparatively high and their preservation extraordinary.

This relative abundance contrasts to the apparent scarcity of coleoid cephalopods reported so far from marine fossil lagerstätten of late Early to Late Cretaceous age (Albian to Santonian) in northeastern and central Mexico. In these fossil sites, lithologies are dominated by laminated platy limestone and intercalated marl, which are best characterized as plattenkalk (Ifrim, 2006; Ifrim et al., 2007). In northeastern Mexico, these deposits crop out in an area of >15,000 square km and were formed under oxygen-deficient conditions of an open shelf along the passive continental margin of the Paleogulf of Mexico (e.g., Ifrim, 2006; Ifrim et al., 2007, 2011a). Even though marine vertebrates are abundant, diverse and well preserved in these fossil lagerstätten, the findings of coleoids have been markedly rare. In the case of belemnites, their general absence appears to be real as at least calcitic rostra should have been preserved in the plattenkalk deposits. Still, no belemnite has yet been found in Upper Cretaceous deposits of Mexico, with the Aptian Neohibolithes thus being the last representative of this important group. The absence of non-belemnoid coleoids, on the other hand, may reflect a preservational bias, as aragonite is generally dissolved in the northeastern Mexican plattenkalk deposits. Ammonite shells are therefore only preserved as flattened moulds or imprints. However, an additional collection bias may also be present. It is important to note that scientific access is difficult to most sites (e.g. in northern Coahuila), which are located in remote and dangerous areas. The few quarry workers mining limestone slabs in these localities preferentially collect decorative and complete fossils (e.g. fishes) which are easy to sell or trade. Both effects may explain why to date, only a single gladius of a octobrachian coleoid (Glyphiteuthis rhinophora) is known from the Cenomanian plattenkalk of the Cuatrocienegas Valley in Coahuila (Fuchs et al., 2010). Another supposed vestige of a cephalopod gladius from Turonian platy limestone at Vallecillo, named Palaeoctopus pelagicus by Fuchs et al., in 2008, was subsequently shown to be a gular plate of a coelacanth fish (Schultze et al., 2010). Here we describe new records of coleoids from the region, two octobrachian gladiuses from the lower to middle Turonian plattenkalk of Vallecillo, located about 150 km east of Cuatrocienegas. We discuss the palaeobiological implications of these new findings and the remarkable length of the two gladiuses.

Section snippets

Geologic setting

Vallecillo (26°39′N 99°59′W) is a small town located about 100 km north of Monterrey, Nuevo León (Fig.1). Platy limestone with millimetric lamination is mined near the village in small quarries. Fossils are abundant in this sediment and marine reptiles (e.g. Buchy et al., 2005, 2007; Ifrim et al., 2008; Frey et al., 2017) but especially fishes (e.g. Giersch, 2014; Stinnesbeck et al., 2019, 2020; Vullo et al., 2021) are regularly found by quarry workers and yield an excellent preservation of

Material & methods

Specimens CPC 2796 and CPC 2797 were discovered in the summer of 2020 by workmen in an active limestone quarry at Vallecillo in early-middle Turonian strata of the Vallecillo Member of the Agua Nueva Formation. The precise stratigraphic position of the specimens is not known to us. Both specimens were collected from local quarrymen and donated to the fossil collector Ing. Mauricio Fernández Garza (Monterrey). He registered the specimens with the Museo del Desierto (MUDE), Saltillo, Mexico,

Systematic paleontology

  • Octobrachia Haeckel, 1866

  • Prototeuthina Naef, 1921

  • Plesioteuthidae Naef, 1921

  • Type genus: Plesioteuthis Wagner, 1859

  • Boreopeltis Engeser & Reitner, 1985

  • Type species: B. helgolandiae Engeser and Reitner, 1985 (lower Aptian, Heligoland, northern Germany)

  • Other species included (after Fuchs and Larson, 2011a):

  • Boreopeltis sagittata Naef, 1921 (lower Tithonian, Solnhofen Plattenkalk, Germany)

  • Boreopeltis smithi Fuchs & Larson, 2011a (upper Cenomanian, Plattenkalks of Lebanon)

  • Boreopeltis ifrimae sp. nov.

Palaeobiological implications

Boreopeltis ifrimae sp. nov. represents the youngest and thus last representative of the genus Boreopeltis. The early Turonian age of the two specimens extents the stratigraphic distribution of the genus Boreopeltis for 4–5 million years.

The prefix Boreo-, established by Engeser and Reitner (1985) for the type species of Boreopeltis, B. helgolandiae, refers to the northern hemisphere occurrence of this taxon. The record of B. smithi in the Cenomanian of Lebanon has already shown that this

Concluding remarks

The two fossils from the Turonian Agua Nueva Formation near Vallecillo (Mexico) represent the gladiuses of octobrachian coleoids (Cephalopoda). The general gladius morphology suggests placement within the prototeuthid genus Boreopeltis Engeser & Reitner, 1985, which depicts the first record of this genus outside the Tethys realm. Gladius proportions are similar to Cenomanian Boreopeltis smithi Fuchs and Larson, 2011a, Fuchs and Larson, 2011b, but a smooth central median field justifies the

Acknowledgements

We are grateful to Ing. Mauricio Fernández Garza who made the specimen accessible for scientific research and supports our paleontological work at Vallecillo. We are also grateful to Christian Klug (Zurich) and an anonymous reviewer for their thoughtful reviews of an earlier version of the manuscript.

References (49)

  • D. Fuchs

    Eromangateuthis n. gen., a new genus for a late Albian gladius-bearing giant octobrachian (Cephalopoda: Coleoidea)

    Paleontological Contributions

    (2019)
  • D. Fuchs

    Part M, Coleoidea, Chapter 23G: Systematic Descriptions: Octobrachia

    Treatise Online

    (2020)
  • D. Fuchs et al.

    The gladiuses in coleoid cephalopods: homology, parallelism, or convergence?

    Swiss Journal of Palaeontology

    (2015)
  • D. Fuchs et al.

    Diversity, morphology, and phylogeny of coleoid cephalopods from the Upper Cretaceous Plattenkalks of Lebanon - Part I: Prototeuthidina

    Journal of Paleontology

    (2011)
  • D. Fuchs et al.

    Diversity, morphology and phylogeny of coleoid cephalopods from the Upper Cretaceous Plattenkalks of Lebanon - Part II: Teudopseina

    Journal of Paleontology

    (2011)
  • D. Fuchs et al.

    Gladius shape variation in coleoid cephalopod Trachyteuthis from the Upper Jurassic Nusplingen and Solnhofen Plattenkalks

    Acta Palaeontologica Polonica

    (2007)
  • D. Fuchs et al.

    Taxonomy, morphology and phylogeny of plesioteuthidid coleoids from the Upper Jurassic (Tithonian) Plattenkalks of Solnhofen

    Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen

    (2007)
  • D. Fuchs et al.

    A new Palaeoctopus (Cephalopoda: Coleoidea) from the Late Cretaceous of Vallecillo, north-eastern Mexico, and implications for the evolution of Octopoda

    Palaeontology

    (2008)
  • D. Fuchs et al.

    New octopods (Cephalopoda: Coleoidea) from the Late Cretaceous (Upper Cenomanian) of Hakel and Hadjoula (Lebanon)

    Palaeontology

    (2009)
  • D. Fuchs et al.

    Glyphiteuthis rhinophora sp. nov., a trachyteuthidid (Coleoidea, Cephalopoda) from the Cenomanian (Late Cretaceous) of Mexico

    Paläontologische Zeitschrift

    (2010)
  • D. Fuchs et al.

    First record of a complete arm crown of the Early Jurassic coleoid Loligosepia (Cephalopoda)

    Paläontologische Zeitschrift

    (2013)
  • D. Fuchs et al.

    The locomotion system of fossil Coleoidea (Cephalopoda) and its phylogenetic significance

    Lethaia

    (2016)
  • S. Giersch

    Die Knochenfische der Oberkreidezeit in Nordost-Mexiko: Beschreibung, Systematik, Vergesellschaftung, Paläooökologie und Paläobiogeographie

    (2014)
  • E.H.P.A. Haeckel

    Generelle Morphologie der Organismen

  • Cited by (0)

    View full text