[Paleontology • 2023] Eoconstrictor barnesi • A New booid Snake from the Eocene (Lutetian) Konservat-Lagerstätte of Geiseltal, Germany, and A New Phylogenetic Analysis of Booidea

 Eoconstrictor barnesi in the Geiseltal palaeoenvironment, trying to capture a small leptictidan mammal 

 Palci, Onary, Lee, Smith, Wings, Rabi & Georgalis, 2023

 DOI: 10.1093/zoolinnean/zlad179 

 twitter.com/DrGeorgalis

Life reconstruction by Márton Szabó

Abstract

We describe two exceptionally preserved fossil snakes from the Eocene Konservat-Lagerstätte of Geiseltal, located in the state of Saxony-Anhalt, Germany. The two snake specimens, GMH LIX-3-1992 and GMH XXXVIII-20-1964, can be confidently identified as booids based on general morphology and were thus compared to other geographically and/or temporally close fossil booids. We found that GMH LIX-3-1992 is morphologically very similar to Eoconstrictor spinifer, also from Geiseltal, and to Eoconstrictor fischeri, from the middle Eocene of Messel, but differs from both in a number of cranial and vertebral features. Based on these differences we erect the new species Eoconstrictor barnesi sp. nov.; GMH XXXVIII-20-1964 is very similar to GMH LIX-3-1992 and the two differ only in features that are likely ontogenetic. Phylogenetic analyses of snakes using maximum parsimony and Bayesian inference on datasets inclusive of both morphological and molecular data consistently support a close affinity of E. barnesi to E. fischeri and E. spinifer. Our preferred phylogenetic hypothesis places the three species of Eoconstrictor in a clade that is sister to Neotropical Boidae, a result consistent with previous studies. The genus Eoconstrictor could provide an important calibration point for molecular clock studies of booids and snakes in general.

Eocene, evolution, computed tomography, phylogeny, Serpentes

SYSTEMATIC PALAEONTOLOGY

Squamata Oppel, 1811a

Serpentes Linnaeus, 1758

Constrictores Oppel, 1811b (sensu  Georgalis and Smith 2020)

Booidea Gray, 1825 (sensu  Pyron et al. 2014)

Genus Eoconstrictor  Scanferla & Smith, 2020a

 

Type species: Palaeopython fischeri  Schaal, 2004 (original combination), currently Eoconstrictor fischeri (Schaal, 2004) following the work of Scanferla and Smith (2020a).

Type species locality and age: Messel Pit, Germany (Smith et al. 2018). All known specimens of E. fischeri come from the lacustrine ‘oil-shale’ of the Middle Messel Formation (near the Ypresian–Lutetian boundary, ~48 Mya) (Lenz et al. 2015).

Eoconstrictor barnesi, GMH XXXVIII-20-1964, holotype.
A, View of the specimen as preserved, insets show clusters of vertebrae that are preserved on the same slab but a few centimetres away from the rest of the body; (B) close-up of the skull in dorsal view and disarticulated left lower jaw in lateral view; (C) close-up of three mid-trunk vertebrae in ventral view; (D) close-up of two posterior trunk vertebrae in ventral view; (E) close-up of four mid-trunk vertebrae in left lateral view; (F) close-up of four mid-trunk vertebrae in dorsal view.

Eoconstrictor barnesi, GMH LIX-3-1992, paratype.
A, View of the specimen as preserved; (B) close-up of the skull in left lateral view; (C) close-up of three precloacal vertebrae in ventral view; (D) close-up of five precloacal vertebrae in left dorsolateral and dorsal views.

  Eoconstrictor barnesi sp. nov.

Etymology: Species epithet honouring Ben Barnes, who pioneered palaeontological excavations and research in the brown coal deposits of Geiseltal in the 1920s, as part of his Ph.D. studies at the Geological Institute of Halle (Saale).

Holotype: GMH XXXVIII-20-1964, a partial skull and partially disarticulated skeleton missing only the most anterior precloacal region, the cloacal region, and most of the tail (Figs 2–5, Supporting Information, File S1: Fig. S1).

Life reconstruction of Eoconstrictor barnesi in the Geiseltal palaeoenvironment, trying to capture a small leptictidan mammal (artwork by Márton Szabó).

Alessandro Palci, Silvio Onary, Michael S Y Lee, Krister T Smith, Oliver Wings, Márton Rabi and Georgios L Georgalis. 2023. A New booid Snake from the Eocene (Lutetian) Konservat-Lagerstätte of Geiseltal, Germany, and A New Phylogenetic Analysis of Booidea. Zoological Journal of the Linnean Society. zlad179. DOI: 10.1093/zoolinnean/zlad179

  twitter.com/DrGeorgalis/status/1735309444601225613

[Paleontology • 2017] The Squamation of the Eocene stem-Basilisk Geiseltaliellus maarius (Squamata: Iguanidae: Corytophaninae) from Messel, Germany

Geiseltaliellus maarius  Smith, 2009

life reconstruction by J. Eberhardt & A. Vogel  (SMF)

Smith, 2017. SALAMANDRA. 53(4) 

Abstract

 An exceptional new specimen of the stem-basilisk Geiseltaliellus maarius from the middle Eocene of Messel, Germany, preserves details of the squamation of this extinct species. The dorsum and extremities were covered by small, rhomoidal scales, about 0.2 mm in size in most places; somewhat larger scales were present on the lower extremities and on the head. Scales of the venter were arranged in transverse rows, unlike in extant Polychrus and Laemanctus. There is some evidence that the scales on the extremities possessed keels, as in extant basilisks and Polychrus. Keratin appears to be preserved in places. The “Oberhäutchen” is nearly featureless, probably the result of postmortem microbial decomposition; scale organs were not observed. Overall, the body of G. maarius possessed a fine, homogeneous squamation most similar to Basiliscus. Possible sexual dimorphism in the form of the parietal crest raises the prospect of a projecting median keel composed of skin in male G. maarius, although direct evidence on this point is currently lacking. The squamation of the tail is discussed in light of the pseudoautotomy shown by this species. 

Key words: Fossils, Corytophanidae, Eocene, scales, keratin.

Figure 1. Skeleton with skin shadows of Geiseltaliellus maarius, SMF ME 11380a (part).
 (A) Detail of temple region of head. (B) Detail of throat or shoulder region. (C) Detail of right lower leg scales (over tibia and fibula). (D) Detail of left lower leg scales (torn downward and preserved around toe). (E) Detail of digit IV of left pes. Scale bar is 5 mm.

Figure 8. Reconstruction of the squamation of male Geiseltaliellus maarius from Messel.

Juliane Eberhardt (SMF) drew the life reconstruction, colored by Anika Vogel (SMF). 

 K. T. Smith. 2017. The Squamation of the Eocene stem-basilisk Geiseltaliellus maarius (Squamata: Iguanidae: Corytophaninae) from Messel, Germany. SALAMANDRA. 53(4); 519–530.  

http://www.salamandra-journal.com/index.php/home/contents/2017-vol-53/1879-smith-k-t/file

  

[Paleontology • 2016] Palaeoamyda messeliana nov. comb. (Testudines, Pan-Trionychidae) from the Eocene Messel Pit and Geiseltal localities, Germany, Taxonomic and Phylogenetic insights

Figure 2: Palaeoamyda messeliana  SMF ME 1211. 
(A) articulated skeleton in dorsolateral view. (B) outline of the carapace and lateral plastral elements in dorsolateral view. (C) close-up of the right hindlimb. (D) close-up of the tail. (E) close-up of the right forelimb.

Abbreviations: co, costal bone; hyo, hyoplastron; hyp, hypoplastron; ne, neural bone; nu, nuchal bone.   

DOI: 10.7717/peerj.2647

Abstract

Background

Abundant pan-trionychid (soft-shell) turtles specimens have been found in Eocene sequences of central Europe, particularly from two localities in Germany, the Messel Pit (a UNESCO World Natural Heritage Site) and Geiseltal, traditionally attributed to Trionyx messelianus or Rafetoides austriacus. Over the last two decades new specimens of this taxon from these two localities have been discovered and fully prepared. However, they have remained unstudied, as well as their phylogenetic position inside Pan-Trionychidae is unknown.

Results

Five new specimens of Palaeoamyda messeliana nov. comb. from Messel Pit and Geiseltal localities are fully described here. A revised diagnosis for the species is also presented here, together with its inclusion in a phylogenetic analysis of Pan-Trionychidae that shows that this species is sister to the extant Amyda cartilaginea, one of the most abundant pan-trionychid (soft-shell) turtles from Asia, both members of the clade Chitrini. The specimens described in here are among the best and most complete fossil pan-trionychid skeletons so far known.

Systematic Paleontology

TESTUDINES Batsch, 1788

CRYPTODIRA Cope, 1868

PAN-TRIONYCHIDAE Sensu Joyce, Parham & Gauthier, 2004

Palaeoamyda nov. gen.

Etymology: A fossil version of the extant genus Amyda, based on the important similarities between these two genera.

Type species: Palaeoamyda (orig. Trionyx) messeliana nov. comb. (Reinach, 1900).

Included species: Palaeoamyda messeliana nov. comb.

Diagnosis: Same as for the type species, Palaeoamyda messeliana nov. comb.

Palaeoamyda messeliana nov. comb. (Reinach, 1900)

Revised diagnosis: Palaeoamyda messeliana nov. comb., shares the following synapomorphies with Pan-Trionychidae: contribution of the jugal to the upper temporal emargination, loss of a contribution of the fused premaxilla to the external nares, absence of carapacial and plastral scutes, the absence of pygal bones, sculpturing pattern that covers all metaplastic portions of the shell bones, V-shape entoplastron. Palaeoamyda messeliana nov. comb. shares with Trionychinae the following synapomorphies: a nuchal bone at least three times wider than long, complete absence of peripheral bones, neural series always containing at least one reversal of neural orientation, and a short bridge. Inside Trionychinae (sensu Meylan, 1987), Palaeoamyda messeliana nov. comb. resembles members of Chitrini in particular Amyda cartilaginea by: having a hypoplastron having only one processus hypoplastrales medialis posterior, a pair of processus cardinus masculi anterior, and a very short processus hypoplastralis medialis anterior, a narrow and well developed metischial process of ischium, a very advanced temporal emargination reducing the area of exposure of parietals at the roof top of the skull. Differs from other chitrinins by the following plesiomorphies: costals 7 having a medial contact between each other for half of more of their total medial margin, a shallow medial notch at the anterior margin of nuchal, seven neurals, with the neural reversal of orientation at neural 6. Potential autapomorphies of Palaeoamyda messeliana nov. comb., suggested by Karl (1998) brachial horn II with several ossifications, triturating surface completely flat or with solid symphyseal notch, entoplastron having acute angle and being straight at symphysis.

Taxonomic history

Trionyx messelianus Reinach, 1900

Trionyx messelianus var. lepsiusi Harassowitz, 1919

Trionyx (Amyda) messelianus var. kochi Hummel, 1927 (new combination)

Rafetoides austriacus Karl, 1997 (junior synonym).

Localities and horizons: SMF ME specimens were collected in the Messel Pit, near Darmstadt, Germany, middle Eocene (early Lutetian, MP11, ∼47 Ma) (Lenz et al., 2015). WDC specimen was collected in Geiseltal locality, Saxony-Anhalt region, Germany. The age for this locality is middle Eocene Haubold & Hellmund (1998). However, not specific information about the horizon or any other details of the collection are known.

Edwin Cadena​. 2016. Palaeoamyda messeliana nov. comb. (Testudines, Pan-Trionychidae) from the Eocene Messel Pit and Geiseltal localities, Germany, Taxonomic and Phylogenetic insights.    PeerJ. 4:e2647. DOI: 10.7717/peerj.2647

[Paleontology • 2016] Fossil Snake, Palaeopython fischeri, Preserving Three Trophic Levels and Evidence for An Ontogenetic Dietary Shift

Abstract

We report a fossil snake from the middle Eocene (48 Ma) Messel Pit, in whose stomach is a lizard, in whose stomach is an insect. This is the second known vertebrate fossil containing direct evidence of three trophic levels. The snake is identified as a juvenile of Palaeopython fischeri on the basis of new characters of the skull; the lizard is identified as Geiseltaliellus maarius, a stem-basilisk; and the insect, despite preserved structural colouration, could not be identified more precisely. G. maarius is thought to have been an arboreal species, but like its extant relatives may have foraged occasionally on the ground. Another, larger specimen of G. maarius preserves plant remains in the digestive tract, suggesting that omnivory in this species may have been common in larger individuals, as in extant Basiliscus and Polychrus. A general picture of the trophic ecology of P. fischeri is not yet possible, although the presence of a lizard in the stomach of a juvenile individual suggests that this snake could have undergone a dietary shift, as in many extant boines.

Keywords: Messel, Middle Eocene, Palaeopython fischeri, Geiseltaliellus maarius, Gut contents, Food chain

Fig. 1 SMF ME 11332a, comprising a juvenile specimen of the snake Palaeopython fischeri and its prey. Arrow points to the tip of the snout of the lizard inside the snake 

Conclusions

In conjunction with dietary data on extant basilisks (Corytophaninae) and phylogenetic position, the consumption of plant matter by larger individuals of G. maarius, an early stem relative of Corytophaninae (Smith 2009), suggests that this propensity might be primitive for Corytophaninae or Corytophaninae + (Polychrus + Anolis) as a whole. This interpretation would be strengthened if Conrad’s (2015) view of the relationships of Geiseltaliellus is correct. Available data suggest dietary shift from insectory to omnivory in G. maarius.

Similarly, in conjunction with the presence of a crocodile in the large boid specimen from Messel studied by Greene (1983), the presence of an arboreal lizard in the alimentary canal of a juvenile individual of P. fischeri indicates that this dietary preference during juvenile stages and perhaps an ontogenetic dietary shift was present in boid snakes since the middle Eocene.

Krister T. Smith and Agustín Scanferla. 2016. Fossil Snake Preserving Three Trophic Levels and Evidence for An Ontogenetic Dietary Shift. Palaeobiodiversity and Palaeoenvironments. DOI:  10.1007/s12549-016-0244-1

   

Amazing ‘Nesting Doll’ Fossil Reveals Bug in Lizard in Snake https://t.co/Do3D4ggFdl via @NatGeo A Messel Turducken!!