Geological Society, London, Special Publications, Jul 17, 2023
Cretaceous limestones near Maastricht (SE Netherlands) have been quarried at least since Roman ti... more Cretaceous limestones near Maastricht (SE Netherlands) have been quarried at least since Roman times. In the late eighteenth century, scientific interest developed in their macrofossil content and specimens were illustrated for the first time. Amongst the early discoveries was a partial skull of a large predatory vertebrate that would play an important role in the emergence of modern palaeontology and our understanding of the concept of extinction. After decades of scientific debate, this animal was recognized as a large extinct marine relative of monitor lizards (varanoids) and named Mosasaurus. A detailed lithostratigraphy of Upper Cretaceous (Santonian–Maastrichtian) rocks was established in the Maastrichtian type area during the mid-1970s, which resulted in a renewed interest in fossil hunting by professional and amateur palaeontologists alike. During recent decades, both micro- and macrofossils have enabled a refinement of biozonations, correlations within the basin and with sections elsewhere, a greater insight into taphonomic processes and updated taxonomic interpretations. A new age model and chemostratigraphical framework is the most recent addition, permitting the placement of geoheritage in a larger frame and intensifying outreach to the public, including also virtual and augmented reality and hands-on experience to visitors of museum and (disused) quarries alike.
Abstract A single, atypical conchorhynch (calcitic tip of a cephalopod lower jaw), recovered from... more Abstract A single, atypical conchorhynch (calcitic tip of a cephalopod lower jaw), recovered from the uppermost Meerssen Member (Maastricht Formation, upper Maastrichtian) at the former ENCI-HeidelbergCement Group quarry, south of Maastricht, is described as a new parataxon, Conchorhynchus illustris sp. nov. The specimen can be differentiated from all previous conchorhynch records on account of its large size, elongated shape and, in particular, of the structure of its apical part which is smooth and forwardly elongated. During the Late Cretaceous, conchorhynchs formed part of the jaw apparatus of nautilids and of two ammonoid suborders, Phylloceratina and Lytoceratina. Since conchorhynchs are most often found separated from jaws, establishing to which group of cephalopods their bearer belonged can be complicated. Here, for the first time, we propose a set of morphological criteria to differentiate clearly between nautiloid and ammonoid conchorhynchs. Although Conchorhynchus illustris sp. nov. is distinct from all currently known nautilid conchorhynchs, the sum of its morphological features is indicative of assignment to that cephalopod group. The upper portion of the Maastricht Formation in the Maastricht area (Nekum and Meerssen members) has yielded internal and external moulds of shells of the nautilid Eutrephoceras Hyatt, 1894 and the hercoglossid Cimomia Conrad, 1866 . The new conchorhynch type described herein most likely belonged to one of these shell-based taxa. Judging from its unusual shape, the feeding strategy of its bearer must have differed from that of modern nautilids, in that it held and pierced prey rather than crushed sturdy shells.
A synthesis of the stratigraphy of the Maastrichtian Stage in its extended type area, that is, so... more A synthesis of the stratigraphy of the Maastrichtian Stage in its extended type area, that is, southern Limburg (the Netherlands), and adjacent Belgian and German territories, is presented with a brief historical overview. Quarrying activities at the large quarry complex of ENCI-HeidelbergCement Group will officially come to an end on July 1, 2018. However, the stratotype section below the Lichtenberg farmstead and directly behind the main office building at the Lage Kanaaldijk (Maastricht), will be preserved, as will various faces within the quarry complex. Strata of Maastrichtian age include the Vijlen, Lixhe 1-3 and Lanaye members of the Gulpen Formation, as well as the Valkenburg, Gronsveld, Schiepersberg, Emael, Nekum and Meerssen members of the Maastricht Formation. The lower Maastrichtian portion is comparatively poorly preserved, being characterised by frequent reworking; only elements of the Belemnella obtusa, Belemnella sumensis and/or Belemnella cimbrica zones (the two last-named representing the traditional Belemnella occidentalis Zone) have been recorded. Belemnitella junior and Belemnitella lwowensis define the upper Maastrichtian, both first appearing in interval 4 of the Vijlen Member. At the ENCI-HeidelbergCement Group quarry, the lower/upper Maastrichtian boundary is placed at c. 5 m above the Zonneberg Horizon on benthic foraminifer evidence; strontium isotope data are in agreement. The highest portion of the Meerssen Member (uppermost IVf-6 and IVf-7) is missing from the type section; this part of the sequence is exposed at the former Curfs quarry (Geulhem), the Berg en Terblijt Horizon being equated with the Cretaceous/Paleogene (K/Pg boundary).
Geological Society, London, Special Publications, Jul 17, 2023
Cretaceous limestones near Maastricht (SE Netherlands) have been quarried at least since Roman ti... more Cretaceous limestones near Maastricht (SE Netherlands) have been quarried at least since Roman times. In the late eighteenth century, scientific interest developed in their macrofossil content and specimens were illustrated for the first time. Amongst the early discoveries was a partial skull of a large predatory vertebrate that would play an important role in the emergence of modern palaeontology and our understanding of the concept of extinction. After decades of scientific debate, this animal was recognized as a large extinct marine relative of monitor lizards (varanoids) and named Mosasaurus. A detailed lithostratigraphy of Upper Cretaceous (Santonian–Maastrichtian) rocks was established in the Maastrichtian type area during the mid-1970s, which resulted in a renewed interest in fossil hunting by professional and amateur palaeontologists alike. During recent decades, both micro- and macrofossils have enabled a refinement of biozonations, correlations within the basin and with sections elsewhere, a greater insight into taphonomic processes and updated taxonomic interpretations. A new age model and chemostratigraphical framework is the most recent addition, permitting the placement of geoheritage in a larger frame and intensifying outreach to the public, including also virtual and augmented reality and hands-on experience to visitors of museum and (disused) quarries alike.
Abstract A single, atypical conchorhynch (calcitic tip of a cephalopod lower jaw), recovered from... more Abstract A single, atypical conchorhynch (calcitic tip of a cephalopod lower jaw), recovered from the uppermost Meerssen Member (Maastricht Formation, upper Maastrichtian) at the former ENCI-HeidelbergCement Group quarry, south of Maastricht, is described as a new parataxon, Conchorhynchus illustris sp. nov. The specimen can be differentiated from all previous conchorhynch records on account of its large size, elongated shape and, in particular, of the structure of its apical part which is smooth and forwardly elongated. During the Late Cretaceous, conchorhynchs formed part of the jaw apparatus of nautilids and of two ammonoid suborders, Phylloceratina and Lytoceratina. Since conchorhynchs are most often found separated from jaws, establishing to which group of cephalopods their bearer belonged can be complicated. Here, for the first time, we propose a set of morphological criteria to differentiate clearly between nautiloid and ammonoid conchorhynchs. Although Conchorhynchus illustris sp. nov. is distinct from all currently known nautilid conchorhynchs, the sum of its morphological features is indicative of assignment to that cephalopod group. The upper portion of the Maastricht Formation in the Maastricht area (Nekum and Meerssen members) has yielded internal and external moulds of shells of the nautilid Eutrephoceras Hyatt, 1894 and the hercoglossid Cimomia Conrad, 1866 . The new conchorhynch type described herein most likely belonged to one of these shell-based taxa. Judging from its unusual shape, the feeding strategy of its bearer must have differed from that of modern nautilids, in that it held and pierced prey rather than crushed sturdy shells.
A synthesis of the stratigraphy of the Maastrichtian Stage in its extended type area, that is, so... more A synthesis of the stratigraphy of the Maastrichtian Stage in its extended type area, that is, southern Limburg (the Netherlands), and adjacent Belgian and German territories, is presented with a brief historical overview. Quarrying activities at the large quarry complex of ENCI-HeidelbergCement Group will officially come to an end on July 1, 2018. However, the stratotype section below the Lichtenberg farmstead and directly behind the main office building at the Lage Kanaaldijk (Maastricht), will be preserved, as will various faces within the quarry complex. Strata of Maastrichtian age include the Vijlen, Lixhe 1-3 and Lanaye members of the Gulpen Formation, as well as the Valkenburg, Gronsveld, Schiepersberg, Emael, Nekum and Meerssen members of the Maastricht Formation. The lower Maastrichtian portion is comparatively poorly preserved, being characterised by frequent reworking; only elements of the Belemnella obtusa, Belemnella sumensis and/or Belemnella cimbrica zones (the two last-named representing the traditional Belemnella occidentalis Zone) have been recorded. Belemnitella junior and Belemnitella lwowensis define the upper Maastrichtian, both first appearing in interval 4 of the Vijlen Member. At the ENCI-HeidelbergCement Group quarry, the lower/upper Maastrichtian boundary is placed at c. 5 m above the Zonneberg Horizon on benthic foraminifer evidence; strontium isotope data are in agreement. The highest portion of the Meerssen Member (uppermost IVf-6 and IVf-7) is missing from the type section; this part of the sequence is exposed at the former Curfs quarry (Geulhem), the Berg en Terblijt Horizon being equated with the Cretaceous/Paleogene (K/Pg boundary).
Turonian strata in the Opole area are well known for their well-preserved invertebrate
fossils. A... more Turonian strata in the Opole area are well known for their well-preserved invertebrate fossils. Amongst the earliest descriptions is Leonhard’s 1897 monograph “Die Fauna der Kreideformation in Oberschlesien”, in which some isolated tetrapod elements, including mosasauroid and plesiosaurian teeth as well as a fragmentary bone named Plesiosauridarum were listed. Part of Leonhard's material is now curated in the collection of the Department of Paleozoology of University of Wrocław. Further, yet undescribed, specimens were found in the collection of the Ruhrmuseum in Essen. At present several plesiosaurian teeth, one mosasauroid tooth and a paddle element (? a plesiosaurian mesopodial) are available. Leonhard assigned the first-named to Polyptychodon interruptus. These are slender, yet conical with strong apicobasal striations, which justify reference to pliosauromorph plesiosaurians. They differ from typically more massive teeth of Late Cretaceous pliosaurids (Brachauchenius/Megacephalosaurus) and those found in coeval strata of the Bohemian Cretaceous Basin (BCB, Czech Republic) and more closely resemble teeth of polycotylids. Interestingly, a similar tooth has recently been described from Turonian strata of the Saxonian Cretaceous Basin (SCB, Germany). So far, mosasauroids are unknown from the SCB; however, a tethysaurine mosasauroid was described from the BCB. A recurved mosasauroid tooth crown, assigned to Liodon anceps by Leonhard (along with a second one tooth that could not be reloacted) shows well-developed carinae, strong lingual folds and finer ornament adapically and a near-smooth labial side with faint facetting. A comparison with coeval, or slightly younger, material from England is needed to assign this material to a genus, or family. Leonhard’s mysterious Plesiosauridarum could not be relocated, yet on the basis of his description and illustration, it can be identified as a damaged mosasauroid vertebra. In conclusion, a diverse marine reptile fauna comprising pliosauromorph plesiosaurs with more slender teeth than those found in coeval strata of the Czech Republic, but similar to a tooth from the SCB and mosasauroids are found. Notably, neither protostegids, which are important faunal components in the SCB and BCB, nor elasmosaurids, which are likewise present in both basins are represented in the material from the lower (lower middle?) Turonian of the Opole area.
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fossils. Amongst the earliest descriptions is Leonhard’s 1897 monograph “Die Fauna
der Kreideformation in Oberschlesien”, in which some isolated tetrapod elements,
including mosasauroid and plesiosaurian teeth as well as a fragmentary bone named
Plesiosauridarum were listed. Part of Leonhard's material is now curated in the
collection of the Department of Paleozoology of University of Wrocław. Further, yet
undescribed, specimens were found in the collection of the Ruhrmuseum in Essen.
At present several plesiosaurian teeth, one mosasauroid tooth and a paddle element
(? a plesiosaurian mesopodial) are available. Leonhard assigned the first-named to
Polyptychodon interruptus. These are slender, yet conical with strong apicobasal
striations, which justify reference to pliosauromorph plesiosaurians. They differ from
typically more massive teeth of Late Cretaceous pliosaurids
(Brachauchenius/Megacephalosaurus) and those found in coeval strata of the
Bohemian Cretaceous Basin (BCB, Czech Republic) and more closely resemble
teeth of polycotylids. Interestingly, a similar tooth has recently been described from
Turonian strata of the Saxonian Cretaceous Basin (SCB, Germany). So far,
mosasauroids are unknown from the SCB; however, a tethysaurine mosasauroid was
described from the BCB. A recurved mosasauroid tooth crown, assigned to Liodon
anceps by Leonhard (along with a second one tooth that could not be reloacted)
shows well-developed carinae, strong lingual folds and finer ornament adapically and
a near-smooth labial side with faint facetting. A comparison with coeval, or slightly
younger, material from England is needed to assign this material to a genus, or
family. Leonhard’s mysterious Plesiosauridarum could not be relocated, yet on the
basis of his description and illustration, it can be identified as a damaged
mosasauroid vertebra. In conclusion, a diverse marine reptile fauna comprising
pliosauromorph plesiosaurs with more slender teeth than those found in coeval strata
of the Czech Republic, but similar to a tooth from the SCB and mosasauroids are
found. Notably, neither protostegids, which are important faunal components in the
SCB and BCB, nor elasmosaurids, which are likewise present in both basins are
represented in the material from the lower (lower middle?) Turonian of the Opole
area.