A mid-Cretaceous land snail Euthema truncatellina sp. nov. (Caenogastropoda, Cyclophoroidea, Diplommatinidae) from Burmese amber

Zootaxa ◽  
2020 ◽  
Vol 4858 (2) ◽  
pp. 295-300
Author(s):  
IGOR A. BALASHOV ◽  
EVGENY E. PERKOVSKY ◽  
DMITRY V. VASILENKO

Diplommatinidae Pfeiffer, 1857 is a speciose family of minute operculate land snails that includes more than 500 extant species occurring mainly in Southeastern Asia and northern Oceania with some species in tropical America and, arguably, in Madagascar (Kobelt 1902; Wenz 1938-1939; Haas 1961; Egorov. 2013; Yamazaki et al. 2013; Neubert & Bouchet 2015; Nurinsiyah & Hausdorf 2017; Páll-Gergely et al. 2017a; Greke, 2017). The fossil record of Diplommatinidae is very sparse; it was recorded from the Miocene of Poland (Harzhauser & Neubauer 2018) and four species were recently described from Cretaceous Burmese amber, being the oldest known diplommatinids (Yu et al. 2018; Hirano et al. 2019; Bullis et al. 2020). 

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Takahiro Hirano ◽  
Kaito Asato ◽  
Shûhei Yamamoto ◽  
Yui Takahashi ◽  
Satoshi Chiba

Abstract Other than hard bones and shells, it is rare for soft tissues to fossilize, but occasionally they are well-preserved in amber. Here, we focus on both modern and fossilized species of the land snail superfamily Cyclophoroidea. Phylogenetic relationships within the Cyclophoroidea were previously studied using extant species, but timing of divergence within the group remains unclear. In addition, it is difficult to observe morphological traits such as the chitinous operculum and periostracum of fossil snails due to their poor preservation potential. Here we describe nine species including a new genus and five new species of well-preserved fossil cyclophoroideans from the mid-Cretaceous Burmese amber. These fossils include not only the shell, but also the chitinous operculum and periostracum, soft body, and excrements. We present the first estimation of divergence time among cyclophoroidean families using fossil records and molecular data, suggesting extreme morphological conservatism of the Cyclophoroidea for nearly 100 million years.


Paleobiology ◽  
1977 ◽  
Vol 3 (3) ◽  
pp. 259-269 ◽  
Author(s):  
David E. Schindel ◽  
Stephen Jay Gould

Poecilozonites (Gastrelasmus) is an important component of the endemic land snail fauna of Pleistocene Bermuda. The type species P. circumfirmatus Redfield usually occurs in sympatry with its congener P. discrepans Pfeiffer, though each species is found alone at several localities. The species are less alike morphologically where they occur together than where they are allopatric. This allopatric convergence and sympatric divergence strongly suggests the biological interaction known as character displacement, often documented for living populations. The relatively complete fossil record of Bermuda offers advantages for studying this phenomenon. Collections can be made from a variety of microhabitats occupied through time. Statistical analysis of 1,600 individuals collected from more than 100 localities indicates that interspecific variation is primarily a function of the presence or absence of a congener and depends to a lesser degree on microhabitat. P. circumfirmatus undergoes a smaller morphological change between allopatry and sympatry than does P. discrepans. Study of relative abundances suggests that P. discrepans may have been competitively inferior, though no functional bases for differences between the species are known.


ZooKeys ◽  
2021 ◽  
Vol 1036 ◽  
pp. 99-120
Author(s):  
Roman J. Godunko ◽  
Alexander V. Martynov ◽  
Arnold H. Staniczek

The small, monophyletic mayfly family Vietnamellidae Allen, 1984 has so far only been known from a few extant species of the genus Vietnamella Tshernova, 1972, which are all distributed in the Oriental Realm (Vietnam, Thailand, China, and India). Herein we report the first fossil record of Vietnamellidae based on a male and female imago from Mid-Cretaceous Burmese amber. We establish the new genus Burmellagen. nov. to accommodate these two new Mesozoic specimens. Their attribution to Vietnamellidae is supported by the rounded shape of the hind wings with arched outer margin, the course of thoracic sutures, and characteristics of venation, especially of MP and Cu of the forewings and associated intercalary veins of the cubital field. At the same time, Burmellagen. nov. clearly differs from Vietnamella by a diminished number of longitudinal and cross veins in the hind wings, and by the different shape of male genitalia. This first fossil record of Vietnamellidae supports an age of at least 100 Ma for this taxon.


2021 ◽  
pp. 1-10
Author(s):  
Igor Balashov

Abstract Five land snails and the borings of marine bivalves are reported from Hkamti (Khamti) amber whose age was recently uranium-lead dated to be ca. 110 Ma, in contrast to the nearby Kachin (‘Burmese’) amber considered to be ca. 99 Ma. Four of the snails belong to Cyclophoridae, and although their condition does not allow unambiguous identification or description of the species, one of them strongly resembles Archaeocyclotus plicatula Asato and Hirano in Hirano et al., 2019 from Kachin amber. The fifth snail, Euthema myanmarica n. sp. (Diplommatinidae), is a representative of a genus that was known exclusively from Kachin amber until now. The genus Euthema Yu, Wang, and Pan, 2018 is revised, with a new synonym, Xenostoma Bullis et al., 2020. The recently described ‘Truncatellina dilatatus’ Yu, 2020 from Kachin amber is placed in Euthema. A comparison of the distinguishing characters of the eight Euthema species is provided. The borings of bivalves in Hkamti amber correspond to the ichnospecies Teredolites clavatus Leymerie, 1842, associated with the bivalve genus Martesia Sowerby, 1824 (Pholadidae), and are common in Kachin amber. Similarity of the malacofauna from Hkamti and Kachin ambers, as well as the presence of numerous, similar Teredolites clavatus, indicates that these ambers were formed in very similar paleoenvironments. This indication suggests that forests with very similar conditions existed throughout the entire Albian to the early Cenomanian, or that the dating of at least one of these amber deposits is incorrect. In the latter case, it would mean that Kachin amber is at least 110 Ma or older. UUID: http://zoobank.org/142f10a2-307f-4053-9b29-8aa18db66219


Zootaxa ◽  
2021 ◽  
Vol 4941 (4) ◽  
pp. 580-586
Author(s):  
XIN-YU CHEN ◽  
HUA-CHUAN ZHANG ◽  
XIAOXIAO SHI

Eminespina burma gen. et sp. nov., is described and illustrated based on a female embedded in Cretaceous Burmese amber of Cenomanian age. Autapomorphic are three unique spines distributed anterior quarter of pronotum from longer posterior part. The new evidence of Batesian mimicry in the insect fossil record is briefly discussed. 


2012 ◽  
Vol 90 (7) ◽  
pp. 875-884 ◽  
Author(s):  
A.B. Edworthy ◽  
K.M.M. Steensma ◽  
H.M. Zandberg ◽  
P.L. Lilley

Terrestrial molluscs have declined globally, often as a result of habitat loss and fragmentation. Many land snails are poor dispersers and exist in isolated habitat patches. The Oregon forestsnail ( Allogona townsendiana (I. Lea, 1838)) coincides with the most densely populated region of British Columbia and is listed as endangered in Canada. To investigate the dispersal distances and habitat-use patterns of Oregon forestsnails, we tagged and tracked 21 adult snails at Langley, British Columbia, for up to 3 years (2005–2008). The maximum daily dispersal distance for a snail was 4.5 m and the maximum displacement that we observed for a snail was 32.2 m during 3 years. Snails occupied home-range areas of 18.4–404.4 m2, often overlapping both forest and meadow habitat. Their home-range sizes were smaller in habitats with high availability of stinging nettle ( Urtica dioica L.), which may be an indicator of high-quality habitat. Our results suggest that the Oregon forestsnail is a relatively sedentary species with limited dispersal ability in its adult stage. Although Oregon forestsnails are likely unable to colonize suitable habitat independently, remnant forest–meadow mosaic patches such as our study site provide valuable habitat for Oregon forestsnail, which are supplementary to large tracts of intact forest where most of their populations are found.


Paleobiology ◽  
1975 ◽  
Vol 1 (2) ◽  
pp. 175-188 ◽  
Author(s):  
Neil B. Todd

Evidence is presented that primitive artiodactyls had a diploid number of 14. The higher diploid numbers of most living artiodactyls are interpreted as resulting from karyotypic fissioning at the times of past adaptive radiations. The fossil record appears to support this contention.An evolutionary sequence of unusual X chromosome transformations has been deduced from the differences that exist among extant species. From these, and from interrelationships of karyotypes, certain phylogenetic revisions are suggested.


2020 ◽  
Vol 61 (2) ◽  
pp. 107-117
Author(s):  
Rodrigo B. Salvador ◽  
Jonathan D. Ablett

A small collection containing thirty-nine lots of South African Streptaxidae land snails is housed in the collection of the Museum of New Zealand Te Papa Tongarewa (NMNZ). This material previously belonged to British/South African malacologist Henry C. Burnup, who either donated it to, or exchanged it with New Zealand-based Swiss malacologist Henry Suter, whose land snail collection was eventually acquired by the NMNZ. The lots contain type specimens of eight taxa (species and subspecies) and are presented herein in the form of an annotated and illustrated catalogue.


Author(s):  
Larisa A. Prozorova

Представлены подробные сведения о четырех местонахождения редкой наземной улитки Eostrobilops coreana (Pilsbry, 1927) на Корейском полуострове и трех в Приморском крае. Впервые показан кальцифильный характер вида. Новое местонахождение вида на п-ове Песчаный (административная территория Владивостока) является наиболее северной точкой распространения рода Eostrobilops Pilsbry, 1927. Ключевые слова: наземные улитки, редкие виды, Приморский край, Красные книги, смешанный хвойно-широколиственный лес, известняки, кальцифильные виды. Data on four localities of the Eostrobilops coreana (Pilsbry, 1927) on Korean Peninsula and Primorye Territory (Russia) are presented. For the first time, calcyphile character of the species is demonstrated. A new revealed site of the species at the Peschany Peninsula (Vladivostok administrative territory) is the most northern locality of the genus Eostrobilops Pilsbry, 1927. Key words: land snails, rare species, Primorye Territory, Red Data Books, mixed coniferous-broadleaved forest, limestone, calcyphile species.


PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1301 ◽  
Author(s):  
Adiël A. Klompmaker ◽  
Roger W. Portell ◽  
Aaron T. Klier ◽  
Vanessa Prueter ◽  
Alyssa L. Tucker

Spider crabs (Majoidea) are well-known from modern oceans and are also common in the western part of the Atlantic Ocean. When spider crabs appeared in the Western Atlantic in deep time, and when they became diverse, hinges on their fossil record. By reviewing their fossil record, we show that (1) spider crabs first appeared in the Western Atlantic in the Late Cretaceous, (2) they became common since the Miocene, and (3) most species and genera are found in the Caribbean region from the Miocene onwards. Furthermore, taxonomic work on some modern and fossil Mithracidae, a family that might have originated in the Western Atlantic, was conducted. Specifically,Maguimithraxgen. nov. is erected to accommodate the extant speciesDamithrax spinosissimus, whileDamithraxcf.pleuracanthusis recognized for the first time from the fossil record (late Pliocene–early Pleistocene, Florida, USA). Furthermore, two new species are described from the lower Miocene coral-associated limestones of Jamaica (Mithrax arawakumsp. nov. andNemausa windsoraesp. nov.). Spurred by a recent revision of the subfamily, two known species from the same deposits are refigured and transferred to new genera:Mithrax donovanitoNemausa, andMithrax unguistoDamithrax. The diverse assemblage of decapods from these coral-associated limestones underlines the importance of reefs for the abundance and diversity of decapods in deep time. Finally, we quantitatively show that these crabs possess allometric growth in that length/width ratios drop as specimens grow, a factor that is not always taken into account while describing and comparing among taxa.


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