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Wyświetlanie 1-10 z 10
Tytuł:
A new early Pliocene murine rodent from the Iberian Peninsula and its biostratigraphic implications
Autorzy:
Pinero, P.
Verzi, D.H.
Powiązania:
https://bibliotekanauki.pl/articles/2082273.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Mammalia
Murinae
biochronology
diversification pattern
early Ruscinian
Europe
Opis:
In the last years, a murine identified as Paraethomys aff. abaigari has been repeatedly recognized in several early Pliocene localities of the Iberian Peninsula. We have revised these occurrences, as well as other samples of similar morphology, and propose that all these records correspond to a new species. We diagnose Paraethomys baeticus sp. nov. based on a large sample from the early Ruscinian site of Baza-1 (Guadix-Baza Basin, Spain). It is a medium-sized representative of the genus, with relatively well-developed longitudinal connections both in upper and lower molars, but incomplete stephanodonty. M1 displays high tubercles t6–t9 and low t4–t8 connections. M1 and, to a lesser extent, M2 have posterior spurs on t1 and t3. The t9 and t12 are absent in M2. In m1, a round islet of enamel between the anteroconid and the protoconid-metaconid is regularly observed, as well as a general lack of medial anteroconid, moderate labial cingulum with large posterior accessory cuspid, and longitudinal spur. The new species differs from other European representatives of the genus Paraethomys mainly in its size, which is intermediate between that of the small-sized Paraethomys meini and the large-sized Paraethomys abaigari. In addition, both the size and relative width are smaller than those of Paraethomys jaegeri. The frequency of posterior spurs on t1 and t3 of M1 and M2 is higher than that of P. meini and lower than that of P. jaegeri. The new species here described represents a key biochronological and biostratigraphic marker, since it is restricted to levels of late early Ruscinian age. Thus, this species is useful for establishing divisions within the early Ruscinian, and becomes a characteristic taxon for the early Pliocene in the terrestrial record of the Iberian Peninsula. Magnetobiostratigraphic correlations suggest a chronological range for P. baeticus sp. nov. between ca. 4.6 and 4.3 Ma.
Źródło:
Acta Palaeontologica Polonica; 2020, 65, 4; 719-731
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Jurassic tettigarctid cicadas from China with a novel example of disruptive coloration
Autorzy:
CHEN, JUN
ZHANG, HAICHUN
WANG, BO
ZHENG, YAN
WANG, XIAOLI
ZHENG, XIAOTING
Powiązania:
https://bibliotekanauki.pl/articles/945441.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
insecta
hemiptera
tettigarctidae
coloration pattern
jurassic
china
daohugou
Opis:
Tettigarctidae is the most primitive family of Cicadoidea, with only two relict species. Although they are relatively well known from Eurasia, Australia, Africa, and South America, their Mesozoic examples are typically preserved only as isolated forewings. Herein, a new genus Sanmai Chen, Zhang, and B. Wang with three new species (Sanmai kongi Chen, Zhang, and B. Wang, S. mengi Chen, Zhang, and B. Wang, and S. xuni Chen, Zhang, and B. Wang) are described based on fossil specimens from the Middle–Upper Jurassic of northeastern China, with well-preserved body structures, forewing and hindwing venations, making it the hitherto best known extinct tettigarctid taxon. The new genus, provisionally assigned to the tribe Turutanoviini, provides some new information about the evolution and palaeobiogeography of Mesozoic Tettigarctidae. The genus Paraprosbole is synonymized with Shuraboprosbole. In addition, the coloration pattern of forewing, prominent on some specimens of Sanmai kongi Chen, Zhang, and B. Wang sp. nov. and Sanmai xuni Chen, Zhang, and B. Wang sp. nov., represents a novel example of disruptive coloration in Tettigarctidae, which can effectively break up the body outline as well as surface, and so likely enabled these cicadas to reduce the detectability of potential predators.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 4; 853-862
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reexamination of the mandibular and dental morphology of the Early Jurassic mammalia form Hadrocodium wui
Autorzy:
Luo, Zhe-Xi
Bhullar, Bhart-Anjan S.
Crompton, Alfred W.
Neander, April W.
Rowe, Timothy B.
Powiązania:
https://bibliotekanauki.pl/articles/2216255.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
dental morphology
Jurassic
China
Hadrocodium
Mammaliaformes
growth pattern
Opis:
CT visualization of the mandible and dentition of Hadrocodium wui, a stem mammaliaform from the Lower Jurassic Lower Lufeng Formation of Yunnan, China has revealed new features not accessible by previous microscopic study of the fossil. Its mandible shows a postdentary trough with an overhanging medial ridge and a short Meckel’s sulcus. An incomplete part of the ectotympanic and possibly a remnant of Meckel’s element are preserved in the postdentary trough. Thus, Hadrocodium is similar to other mammaliaforms in retaining a mandibular middle ear, contrary to our earlier interpretation. The mandible exhibits a large postcanine diastema from shedding of anterior premolars without replacement, an age-dependent feature better developed in older adults. Another adult feature is the alignment of the ultimate molar to the coronoid process. This is consistent with age-dependent changes in other mammaliaforms where the last molars of the toothrow shift from medial of the coronoid process in the juvenile, to a position in front of the coronoid process in the adult. The mandible has a short mobile symphysis. The dentition consists of I5, C1 (two-rooted), P3 (including P1 position) and M2 (M2 with confluent roots), and i4, c1 (partially two-rooted), p3, and m2 (m2 with partially confluent roots). The two-rooted upper canines are more derived than other Early Jurassic mammaliaforms from the same fauna, although similar to docodontans. Hadrocodium is unique in that the lower m2 cusp a occludes in the embrasure between upper M1–M2, but the posterior part of m2 shows between-cusp occlusion with upper M2 main cusp A. M2 is half the size of the lower m2, and occludes only with the distal half of m2. The upper postcanines show a steep gradient of posteriorly decreasing tooth size, more so than other mammaliaforms. The CT examination corroborates that there are no unerupted teeth in the upper or lower jaws, and the holotype of H. wui is dentally and osteologically mature and capable of independent feeding.
Źródło:
Acta Palaeontologica Polonica; 2022, 67, 1; 95-113
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First colour-patterned strophomenide brachiopod from the earliest Devonian of Podolia, Ukraine
Autorzy:
Balinski, A.
Powiązania:
https://bibliotekanauki.pl/articles/20963.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
brachiopod
Brachiopoda
Strophomenida
colour pattern
Devonian
Podolia
Ukraine
Opis:
Retained colour pattern on the shells of Plectodonta sp. from the earliest Devonian of Podolia (Ukraine) is the first finding for strophomenide brachiopods and the oldest among articulate brachiopods. The colour pattern in Plectodonta sp. is composed of small, round, brownish spots scattered rather irregularly on the ventral valve only. This may suggest that the described pattern probably performed a protective function through disruptive camouflage against visual systems of potential predators. The occurrence of the colour pattern in Plectodonta sp. exclusively on the ventral valve strongly suggests that these brachiopods lived with the patterned (and convex) ventral valve upwards and the patternless concave dorsal valve facing to the underlying substrate. It thus contradicts a general assumption that concavo−convex brachiopods lived with their convex valves resting on the sediment.
Źródło:
Acta Palaeontologica Polonica; 2010, 55, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Osteohistology of hyperodapedontine rhynchosaurs from the Upper Triassic of Southern Brazil
Autorzy:
Veiga, F.H.
Soares, M.B.
Sayao, J.M.
Powiązania:
https://bibliotekanauki.pl/articles/19977.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
hyperodapedontine rhynchosaur
rhynchosaur
Diapsida
Archosauromorpha
Rhynchosauria
Hyperodapedontinae
bone histology
growth pattern
Triassic
Brazil
Opis:
The first osteohistological study focused exclusively on rhynchosaurs (non-archosauriform archosauromorphs), based on the hyperodapedontines Teyumbaita sulcognathus and Hyperodapedon sp., from the Upper Triassic of Southern Brazil, indicates a relatively rapid growth rate in early ontogeny shown by the fibrolamellar complex, with a change to slow intermittent growth during late ontogeny represented by parallel-fibred bone with several growth marks. Contrary to previous studies, which described a typical non-archosaur reptilian bone tissue pattern for rhynchosaurs, with growth marks extending across the entire cortex, we demonstrate that, in both studied taxa, the initial growth rate was faster in comparison to the later. This suggests that the ability of rapid growth at high rates was already present in basal non-ar-chosauriform archosauromorphs.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Growth and life habits of the Triassic cynodont Trirachodon, inferred from bone histology
Autorzy:
Botha, J
Chinsamy, A.
Powiązania:
https://bibliotekanauki.pl/articles/22174.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
histology
cynodont
Triassic
growth pattern
bone
life style
Trirachodon
growth
life habit
paleontology
Opis:
Growth pattern and lifestyle habits of the Triassic non−mammalian cynodont Trirachodon are deduced from bone histology and cross−sectional geometry. Several skeletal elements of Trirachodon were examined in order to document histological changes during ontogeny, as well as histovariability in the skeleton. The bone histology of all the elements consists of a moderately vascularized, periodically interrupted, fibro−lamellar bone tissue. This suggests that the overall growth of Trirachodon was probably rapid during the favourable season, but decreased or ceased during the unfavourable season. As the environment is thought to have been semi−arid with seasonal rainfall, it is possible that Trirachodon was sensitive to such environmental fluctuations. Some inter−elemental histovariability was noted where the number and prominence of growth rings varied. Limb bone cross−sectional geometry revealed a relatively thick bone wall and supports earlier proposals that Trirachodon was fossorial.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Minute Silurian oncocerid nautiloids with unusual colour patterns
Autorzy:
Manda, S
Turek, V.
Powiązania:
https://bibliotekanauki.pl/articles/22242.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Silurian
paleontology
oncocerid nautiloid
nautiloid
colour pattern
Cephalopoda
Nautiloidea
taxonomy
shell size
shell malformation
Opis:
A minute Silurian oncocerid Cyrtoceras pollux, from the Prague Basin is assigned here to the genus Pomerantsoceras. The only so far known species of this genus comes from the Upper Ordovician (Hirnantian) of Estonia. Pomerantsoceras thus represents, except for un−revised poorly understood taxa, the single known oncocerid genus surviving the end−Ordovician extinction events. Cyrtoceras pollux is unusual among the Silurian nautiloids because of its small shell. Colour pattern characterised by a few longitudinal bands on the entire circumference of the shell is here reported in oncocerids. Longicone and only slightly curved small shells as in Pomerantsoceras are unusual among nautiloids and resemble straight shells of orthocerids and pseudorthocerids, in which the colour pattern consists of straight colour bands. Consequently the shell shape as well as the colour pattern should be regarded as adaptive convergence with orthocerids and pseudorthocerids. It supports the hypothesis that colour pattern functioned as camouflage and its evolution was under adaptive control. In addition, several types of the shell malformations including anomalous growth of septa, shell wall and pits on an internal mould are described.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 3; 503-512
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Colour patterns in Early Devonian cephalopods from the Barrandian Area: Taphonomy and taxonomy
Autorzy:
Turek, V
Powiązania:
https://bibliotekanauki.pl/articles/21864.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
colour pattern
Early Devonian
Devonian
cephalopod
Barrandian area
taphonomy
taxonomy
Bohemia
paleontology
Cephalopoda
Nautiloidea
fossil
Opis:
Five cephalopod specimens from the Lower Devonian of Bohemia (Czech Republic) preserve colour patterns. They include two taxonomically undeterminable orthoceratoids and three oncocerid nautiloids assigned to the genus Ptenoceras. The two fragments of orthocone cephalopods from the lowest Devonian strata (Lochkovian, Monograptus uniformis Zone) display colour patterns unusual in orthoceratoids. They have irregular undulating and zigzag strips that are preserved on counterparts of adapertural regions of specimens flattened in shale, despite their original aragonitic shell having been completely dissolved. These are probably the result of the proteinous pigment inside the shell wall, being substituted during diagenesis by secondary minerals leaving only an altered trace of the original shell. Orthoceratoids from sediments unsuitable for preservation of this feature discussed here thus demonstrate an exceptional case of preservation of colour patterns, not only within Devonian cephalopods but also within other Devonian molluscs. Three specimens of Ptenoceras that preserve colour patterns come from younger Lower Devonian strata. Oblique spiral adaperturally bifurcating bands are preserved in P. alatum from the Pragian and zigzags in P. nudum from the Dalejan. Juvenile specimen of Ptenoceras? sp. from the Pragian exhibits highly undulating transversal bands—a pattern resembling colour markings in some Silurian oncocerids. Dark grey wavy lines observed on the superficially abraded adapical part of a phragmocone of nautiloid Pseudorutoceras bolli and interpreted formerly to be colour markings are here reinterpreted as secondary pigmented growth lines. Other Devonian fossils including a single brachiopod and several gastropods from the Barrandian Area with preserved colour patterns are mentioned. Variety of cephalopod colour patterns, their taxonomic significance, function and significance for palaeoecological interpretation, palaeoenvironmental conditions favouring colour pattern preservation and systematic affiliation of taxa with colour pattern preserved are discussed.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 3; 491-502
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fossil population structure and mortality analysis of the cave bears from Ursilor Cave, north-western Romania
Autorzy:
Robu, M.
Powiązania:
https://bibliotekanauki.pl/articles/20701.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
fossil
population structure
mortality analysis
cave bear
Mammalia
Ursus spelaeus
cave taphonomy
death pattern
sex ratio
Ursilor Cave
Romania
Carpathians Mountains
Opis:
Research in cave bear palaeobiology focusing on population structure and mortality analysis may improve our understanding regarding the ecology of this species which vanished at the end of Marine Isotope Stage (MIS) 3, prior to Last Glacial Maximum (LGM), if assessed populations are large enough. Such population is available in Urşilor Cave, from north-western Romania, known as one of the most rich and complex European MIS3 cave bear sites. From the palaeontological excavation, situated at the lower level of the cave (= Scientific Reserve), more than 210 cave bear isolated lower molars, 160 mandibles and almost 180 canines were extracted and analyzed. The results obtained on the wear stages of the studied molars and mandibles indicated an “L”-shaped curve and suggest a non-attritional death pattern and a bone assemblage juvenile dominated. Moreover, the sex-ratio of upper and lower canines indicates a net dominance of females (5.4 females: 1 male). Although a “catastrophic” death pattern was obtained for cave bears, the animals seem to have died diachronically (non-simultaneously), over a time span of more than 6000 years. The triangular graph of age distribution is not appropriate for death assemblages from traps such as karst caves, where taphonomic processes like predation or scavenging would have played a less important role.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Taxonomic implications of the residual colour patterns of ampullinid gastropods and their contribution to the discrimination from naticids
Autorzy:
Caze, B.
Merle, D.
Le Meur, M.
Pacaud, J.-M.
Ledon, D.
Sain Martin, J.-P.
Powiązania:
https://bibliotekanauki.pl/articles/20897.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
taxonomy
residual colour pattern
ampullinid gastropod
gastropod
contribution
discrimination
naticid
Ampullinidae
Naticidae
shell
evolution
Cainozoic
Europe
Ampullina
Globularia
Crommium
Amaurellina
Pachycrommium
Amauropsina
Ampullonatica
Eocernina
Ampullinopsis
Vanikoropsis
Pictavia
Ampullospira
Deshayesia
Cernina
Opis:
The diversity of residual colour patterns is revealed for the first time in the European fossil Ampullinidae. The colour patterns were studied under Ultraviolet (UV) light in approximately 3100 specimens belonging to 83 species, 12 genera (Ampullina, Globularia, Crommium, Amaurellina, Pachycrommium, Amauropsina, Ampullonatica, Eocernina, Ampullinopsis, Vanikoropsis, Pictavia, and Ampullospira) and three subgenera (Globularia, Deshayesia, and Cernina within the genus Globularia). Forty−six Cainozoic species revealed residual colour patterns and 29 of them, belonging to six genera (Ampullina, Globularia, Crommium, Amaurellina, Pachycrommium, Amauropsina), are described herein as examples representing the entire diversity of the encountered colour patterns. These patterns are most diverse during the Middle Eocene coincident with the period of highest taxonomic diversity of the Ampullinidae. Four basic classes, regarded as containing possible homologous colour patterns in terms of pigments incorporation modalities, are proposed. Class I, a fluorescent wide diffuse area or spiral stripes, occurs in most of the species, while the three others are more peculiar. Class II, fluorescent axial zigzagging stripes, Class III, fluorescent axial to slightly opisthocline stripes or segments, and Class IV, fluorescent patches forming axial segments by coalescence, allow an easy distinction between the genera Globularia, Pachycrommium, and three peculiar species of Ampullina. The bauplan of the colour patterns revealed in Globularia is very similar to that of the single extant species, Globularia (Cernina) fluctuata. This supports the view of previous authors who classified them in the same genus. Furthermore, at the family level, the peculiar residual patterns belonging to classes II, III, and IV have not been observed in naticid gastropods. Thus our results for the Cainozoic fossil record are consistent with the conclusions based on anatomy and feeding habits, namely that ampullinid gastropods, regarded for a long time as belonging to the family Naticidae, constitute a family apart.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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