Mesozoic

Leptilostis, a replacement name for Tetillopsis Hong, 1982 (Coleoptera: Curculionidae), junior homonym of Tetillopsis Schrammen, 1910 (Porifera: Tetillidae)

2024-06-30T14:43:59+12:00

Schrammen (1910) described a genus of fossil tetillid sponge, naming it Tetillopsis Schrammen, 1910, and described two species from north-western Germany, viz., T. doeringi Schrammen and T. longitridens Schrammen. Tetillopsis doeringi was later designated as the type species of the genus (de Laubenfels, 1955); and this name is still used in current taxonomic practice (https://paleobiodb.org/classic/basicTaxonInfo?taxon_no=2987 The Paleobiology Database 2024).

**Mandibular biomechanics of Acheroraptor temertyorum (Theropoda: Dromaeosauridae) with implications for the feeding ecology and behaviour**

2024-09-27T23:24:07+12:00

Acheroraptor temertyorum is a dromaeosaurid theropod, probably a saurornitholestine, found in the upper Maastrichtian Hell Creek Formation of Montana. This enigmatic dromaeosaurid is known from only a partial maxilla and dentary, as well as referred isolated teeth, making even the general aspects of its palaeobiology largely elusive. In this work, beam theory is applied to the lower jaw of Acheroraptor temertyorum to document the biomechanical properties of the mandible of this taxon and to infer the feeding mechanism of this dinosaur. This work suggests the lower jaw of Acheroraptor temertyorum is mainly adapted to produce rapid, slashing bites, as previously inferred for other dromaeosaurids. Intriguingly, despite having a closer phylogenetic affinity with Saurornitholestes langstoni, overall biomechanical properties of the lower jaw of Acheroraptor temertyorum are found to be weaker than the former taxon, but rather comparable to Asian velociraptorines. Such results may indicate Acheroraptor temertyorum preyed on smaller animals compared to other saurornitholestines, and suggest diets or predation methods of saurornitholestine dromaeosaurids might have been more diverse than previously assumed.

**Tritor vascular tubules in a holocephalan tooth plate (Ischyodus sp.) from the Cretaceous of Mississippi, USA**

2024-09-27T23:31:30+12:00

A fossil chimaeroid tooth plate (Ischyodus sp.) from the Cretaceous of Frankstown, Mississippi shows exceptional preservation of tritor microstructure. Diagenetic loss of the petrodentine/whitlockin in this specimen has revealed the ultrastructure of the vascular tubule networks of tritor interior structure. The observation that vascular tubes running through the hard tissues of chimaeroid tritors host odontoblast cells supports the hypothesis of an odontoblastic origin for chimaeroid tritor tissue.

**Cranial anatomy and holotype reconstruction of the Late Cretaceous turtle, Australobaena chilensis from the Quiriquina Formation, Chile**

2024-09-13T16:49:08+12:00

Resolving the phylogeny of fossil turtles is uniquely challenging given the high potential for the unification of convergent lineages due to systematic homoplasy. Equivocal reconstructions of turtle evolution and biogeographic or palaeo-climatic data with phylogenetic hypotheses and new images of the holotype reconstructions of fossil turtles are important for prehistoric turtle fossil remains. Here we describe the cranial anatomy and holotype reconstruction of the Late Cretaceous turtle, Australobaena chilensis from the Quiriquina Formation of the Maastricht Ocean Horizon Chile, which was identified as a new genus and species of Baenidae (an extinct family of para-cryptodiran turtles) in 2002 by Karl and Tichy. The holotype is “SMF R 415”, a partially destroyed skull without a lower jaw, and with a unique cranial plane. This taxon belongs to Baenidae, an extinct freshwater family from the Cretaceous period in North America. This is the first baenid fossil found outside of North America, and we re-describe and reconstruct it with new photographs and illustrations of the cranial anatomy of this material (Holotype).

**Three new species of Multistria from mid-Cretaceous amber of northern Myanmar (Hemiptera: Fulgoromorpha: Mimarachnidae)**

2024-10-17T09:11:31+13:00

The extinct planthopper family Mimarachnidae is well represented in mid-Cretaceous Kachin amber of northern Myanmar. In this study, three new species of mimarachnid planthoppers are described and illustrated from Kachin amber, all belonging to the genus Multistria Zhang, Yao & Pang, 2021. The new species, Multistria irregularis sp. nov., M. juanae sp. nov., and M. fionae sp. nov., are primarily distinguished from each other mostly by tegminal characters, such as the branching pattern of the secondary veinlet meshwork, venation, and the colour patterns, as well as differences in head. The tegminal diagnostic characters of Multistria are briefly examined.

Three new lithobiomorphan centipede specimens from mid-Cretaceous Myanmar amber, a clue on the geological record of Lithobiomorpha

2024-11-19T03:01:26+13:00

Chilopoda, part of Myriapoda, is a species-rich group of ~3300 formally described species. Yet, the phylogenetic relationship of centipedes is not fully clear, and the scarceness of their fossil record, compared to the closely related Diplopoda, is a major challenge for understanding their evolutionary history. Within Chilopoda, Lithobiomorpha is one of the most problematic concerning its fossil record, so far restricted to the Cenozoic (~40 mya) and with a single lithobiomorphan-like specimen from Kachin amber (~100 mya). Here, we report three new exceptionally well-preserved lithobiomorphan specimens from Myanmar amber (~100 mya). These represent the first report of oldest representatives of Henicopidae from the Cretaceous, and with this the oldest definite record of Lithobiomorpha. Two specimens have ten pairs of walking legs (stage IV), and one has a fully developed trunk. These specimens are similar in many aspects to the extant group of Henicopidae and, more precisely, to Lamyctes Meinert, 1868. The specimens seemingly lack ocelli, exhibit ~14 (stage IV) and 24 antenna articles, have 2+2 coxosternite teeth, and present tooth-like setae on their coxosternite margins (=porodont). The fully developed specimen possesses a tibial spinose projection on each tibia of legs 1–11, a blunt projection on the tibia of leg 12, and undivided tarsi on their legs 1–12. With the finding of these specimens, we expand the fossil record of Lithobiomorpha significantly.

Rotularia (Annelida: Sabellida: Serpulidae) attached to the mid-Cretaceous Burmese amber

2024-12-18T08:47:44+13:00

Rotularia Defrance is a common extinct genus of planispirally coiled fossil polychaete worms in the family Serpulidae from shallow marine environment. Here, we describe a large collection of Rotularia specimens attached to mid-Cretaceous Burmese amber. The fossil record of Rotularia serves as a valuable tool for calibrating polychaete evolution and suggests that the Burmese amber forest was likely situated not far from the seashore.

Checklist of the Cretaceous gymnospermous wood (updated December 2024)

2024-12-05T11:31:47+13:00

A list of all known fossil wood taxa recorded from the Cretaceous, up to December of 2024, is given. The list contains 57 genera and 317 species of gymnospermous wood described from 48 countries across seven continents. 39 genera and 165 species were reported from Asia, 28 genera and 67 species from Europe, 33 genera and 48 species from Africa, 20 genera and 48 species from North America, 13 genera and 35 species from South America, 4 genera and 4 species from Australia and 5 genera and 12 species from Antarctica. 54 genera and 171 species were documented from the Lower Cretaceous, and 26 genera and 76 species from the Upper Cretaceous. Systematically, 1 genus and 2 species belong to Cycadales, 1 monotypic genus belongs to Bennettitales, 2 genera and 3 species belong to Ginkgoales, 52 genera and 306 species are of Coniferales, and 1 genus and 3 species are incertae sedis.