| 1. |
- Doguzhaeva, Larisa, et al.
(författare)
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A unique late Eocene coleoid cephalopod Mississaepia from Mississippi, USA: New data on cuttlebone structure, and their phylogenetic implications.
- 2014
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Ingår i: Acta Palaeontologica Polonica. - Poland : Polska Akademia Nauk Instytut Paleobiologii (Institute of Paleobiology, Polish Academy of Sciences). - 0567-7920 .- 1732-2421. ; 59:1, s. 147-162
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Tidskriftsartikel (refereegranskat)abstract
- A new family, Mississaepiidae, from the Sepia–Spirula branch of decabrachian coleoids (Cephalopoda), is erected on the basis of the following, recently revealed, morphological, ultrastructural and chemical traits of the cuttlebone in the late Eocene Mississaepia, formerly referred to Belosaepiidae: (i) septa are semi−transparent, largely chitinous (as opposed to all other recorded cephalopods having non−transparent aragonitic septa); (ii) septa have a thin lamello−fibrillar nacreous covering (Sepia lacks nacre altogether, Spirula has fully lamello−fibrillar nacreous septa, ectochochleate cephalopods have columnar nacre in septa); (iii) a siphonal tube is present in early ontogeny (similar to siphonal tube development of the Danian Ceratisepia, and as opposed to complete lack of siphonal tube in Sepia and siphonal tube development through its entire ontogeny in Spirula); (iv) the lamello−fibrillar nacreous ultrastructure of septal necks (similar to septal necks in Spirula); (v) a sub−hemispherical protoconch (as opposed to the spherical protoconchs of the Danian Ceratisepia and Recent Spirula); (vi) conotheca has ventro−lateral extension in early ontogenetic stages (as opposed to Sepia that has no ventro−lateral extention of the conotheca and to Spirula that retains fully−developed phragmocone throughout its entire ontogeny). Chitinous composition of septa in Mississaepia is deduced from (i) their visual similarity to the chitinous semi−transparent flange of Sepia, (ii) angular and rounded outlines and straight compressive failures of the partial septa and mural parts of septa similar to mechanically−damaged dry rigid chitinous flange of Sepia or a gladius of squid, and (iii) organics consistent with [1]−chitin preserved in the shell. The family Mississaepiidae may represent a unknown lineage of the Sepia–Spirula branch of coleoids, a conotheca lacking a nacreous layer being a common trait of the shell of this branch. However, Mississaepiidae is placed with reservation in Sepiida because of similarities between their gross shell morphology (a cuttlebone type of shell) and inorganic−organic composition. In Mississaepia, as in Sepia, the shell contains up to 6% of nitrogen by weight; phosphatised sheets within the dorsal shield may have been originally organic, like similar structures in Sepia; accumulations of pyrite in peripheral zones of aragonitic spherulites and in−between the spherulites of the dorsal shield may also indicate additional locations of organics in the shell of living animal.
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| 2. |
- DOGUZHAEVA, Larisa, et al.
(författare)
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An Eocene orthocone from Antarctica shows convergent evolution of internally shelled cephalopods
- 2017
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Ingår i: PLOS ONE. - San Fransisco : Public Library of Science (PLoS). - 1932-6203. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe Subclass Coleoidea (Class Cephalopoda) accommodates the diverse present-day internally shelled cephalopod mollusks (Spirula, Sepia and octopuses, squids, Vampyroteuthis) and also extinct internally shelled cephalopods. Recent Spirula represents a unique coleoid retaining shell structures, a narrow marginal siphuncle and globular protoconch that signify the ancestry of the subclass Coleoidea from the Paleozoic subclass Bactritoidea. This hypothesis has been recently supported by newly recorded diverse bactritoid-like coleoids from the Carboniferous of the USA, but prior to this study no fossil cephalopod indicative of an endochochleate branch with an origin independent from subclass Bactritoidea has been reported.Methodology/Principal findingsTwo orthoconic conchs were recovered from the Early Eocene of Seymour Island at the tip of the Antarctic Peninsula, Antarctica. They have loosely mineralized organic-rich chitin-compatible microlaminated shell walls and broadly expanded central siphuncles. The morphological, ultrustructural and chemical data were determined and characterized through comparisons with extant and extinct taxa using Scanning Electron Microscopy/Energy Dispersive Spectrometry (SEM/EDS).Conclusions/SignificanceOur study presents the first evidence for an evolutionary lineage of internally shelled cephalopods with independent origin from Bactritoidea/Coleoidea, indicating convergent evolution with the subclass Coleoidea. A new subclass Paracoleoidea Doguzhaeva n. subcl. is established for accommodation of orthoconic cephalopods with the internal shell associated with a broadly expanded central siphuncle. Antarcticerida Doguzhaeva n. ord., Antarcticeratidae Doguzhaeva n. fam., Antarcticeras nordenskjoeldi Doguzhaeva n. gen., n. sp. are described within the subclass Paracoleoidea. The analysis of organic-rich shell preservation of A. nordenskjoeldi by use of SEM/EDS techniques revealed fossilization of hyposeptal cameral soft tissues. This suggests that a depositional environment favoring soft-tissue preservation was the factor enabling conservation of the weakly mineralized shell of A. nordenskjoeldi.
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| 3. |
- Doguzhaeva, Larisa, et al.
(författare)
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Arm hooks and structural features in the Early Permian Glochinomorpha Gordon 1971, indicative of its coleoid affiliation.
- 2014
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Ingår i: Lethaia. - Springer : Scandinavian University Press / Universitetsforlaget AS. - 0024-1164 .- 1502-3931.
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Tidskriftsartikel (refereegranskat)abstract
- Data on the re-examined-type specimens of the Early Permian Glochinomorpha stifeli Gordon 1971 (Coleoidea, Cephalopoda) gives new insight into the evolutionary origination of gladius-bearing coleoids in the Late Palaeozoic and suggests their parallel evolution with the belemnoids and phragmoteuthids. The iron-oxidized arm hooks are found in front of a gladius on an un-illustrated paratype (USNM 170614). Theyare dispersed in a maximum distance equal to 2.5 the gladius length from the incomplete anterior end of the rachis of the gladius. The hook height ranges from less than 1 mm to as much as 4 mm. They have a massive curved base, and a strongly curved shaft with a long thin distal part. The hooks confirm the cephalopod and the coleoid affiliation of G. stifeli that is widely rejected. The iron-oxidized gladii (preserved length is less than 20 mm) show micro-laminations and a fibrous ultrastructure; the fibre bundles are approximately 0.5 lm thick. Lack of calcium and the high content of nitrogen (up to 12% of total weight) confirm the originally non-biomineralized (apparently chitin) composition of the gladii suggested by their fibrous ultrastructure. These data lead to the conclusion that in the evolutionary history of gladius-bearing coleoids, the biomaterial (biochemical) development of the skeleton preceded its morphological transformation. This phenomenon resulted in a recombination of an advanced composition (being non-biomineralized) with archaic features (sensu morphological structure of the posterior part) in the gladius of G. stifeli. The data castdoubt on the hypothesized origination of a gladius from a phragmoteuthid pro-ostracum as well as the evolutionary origination of the gladius-bearing coleoids from pro-ostracum-bearing phragmoteuthids or belemnitids.
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| 4. |
- Doguzhaeva, Larisa, et al.
(författare)
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Beak from the body chamber of the Early Carboniferous (Visean) shelled longiconic coleoid (Cephalopoda) from Arkansas, USA : -
- 2017
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Ingår i: Lethaia. - : Scandinavian University Press / Universitetsforlaget AS. - 0024-1164 .- 1502-3931.
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Tidskriftsartikel (refereegranskat)abstract
- Here we report the discovery of an Early Carboniferous (Late Visean) 3D cephalopod beak displaying significant similarity to the lower beak of Recent coleoids. It was uncovered in a fragmentarily preserved, longiconic shell from the Moorefield Formation in Arkansas, USA. This shell comprises a fractured 29-mm-long body chamber having a maximum diameter of ~14 mm and showing an indistinct pro-ostracum-like structure. The beak-bearing shell could easily have been mistaken for a bactritid or orthocerid if it were not for a coleoid-type, weakly mineralized, evidently organic-rich shell wall which shows a lamello-columnar ultrastructure of a bulk of shell wall thickness and plate ultrastructure of thin outer layer. The specimen is assigned to an as-yet unnamed shelled coleoid of a so far unknown high-level taxonomic group. A partially exposed, 4.0-mm-long portion of the beak is the lower beak in oblique view from its left side. It exhibits fractured anthracite-like black, apparently originally chitin material, helmet-like general shape, broad hood with narrow shallow median groove and small notch posteriorly, pronounced pointed, non-biomineralized upside belt rostrum, high shoulder and about a 90–100 degrees jaw angle. A broad hood and massive rostrum emphasize its similarity to the lower mandible of Recent Vampyroteuthis and signify that its unique, among living coleoids, structure has been existed for at least since Late Visean time (~333 my).
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| 5. |
- Doguzhaeva, Larisa, et al.
(författare)
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Connecting stripes: An organic skeletal structure in Sepia from Red Sea
- 2012
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Ingår i: Geobios. - : Elsevier BV. - 0016-6995 .- 1777-5728. ; 45, s. 13-17
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Tidskriftsartikel (refereegranskat)abstract
- The skeletal structure, herein termed ‘‘connecting stripes’’, is demonstrated in dried cuttlebones of Sepia (Acanthosepion) savignyi de Blainville from the Gulf of Aqaba, Red Sea, Eilat, Israel. This structure consists of segmented chitinous strip-like sheets covering the outside opening to the cuttlebone chambers. Scanning electron microscope images demonstrate that the connecting stripes are tightly attached to the neighbouring septa along the septal edges and do not continue from one chamber to the next. When broken, they leave band-like remnants along the attachment sites. The connecting stripes consist of fibrous, organic, possibly mainly chitinous, laminas. Chemical analysis using energy dispersive spectrometry shows that the connecting stripes contain C, O, Na, K but lack Ca and P. The connecting stripes show perceptible, usually barely visible micropores with diameter of ca. 0.1 mm; distances between the micropores are 0.2 to 0.3 mm. The connecting stripes in Sepia are similar to connecting rings in bactritoids and ammonoids in having a segmented structure and a non-mineralized, organic composition. The microporosity of connecting stripes observed in Sepia has been also recorded in three genera of Mesozoic ammonoids. The connecting stripes may serve as a transport route of the cameral liquid in and out of the chambers and are considered to be a homologue of the connecting rings in cephalopods with a fully developed siphonal tube.
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| 6. |
- Doguzhaeva, Larisa, et al.
(författare)
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Embryonic shell structure of Early–Middle Jurassic belemnites, and its significance for belemnite expansion and diversification in the Jurassic.
- 2014
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Ingår i: Lethaia. - : Scandinavian University Press / Universitetsforlaget AS. - 0024-1164 .- 1502-3931. ; 47, s. 49-65
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Tidskriftsartikel (refereegranskat)abstract
- Early Jurassic belemnites are of particular interest to the study of the evolution of skeletal morphology in Lower Carboniferous to the uppermost Cretaceous belemnoids, because they signal the beginning of a global Jurassic–Cretaceous expansion and diversification of belemnitids. We investigated potentially relevant, to this evolutionary pattern, shell features of Sinemurian–Bajocian Nannobelus, Parapassaloteuthis, Holcobelus and Pachybelemnopsis from the Paris Basin. Our analysis of morphological, ultrastructural and chemical traits of the earliest ontogenetic stages of the shell suggests that modified embryonic shell structure of Early–Middle Jurassic belemnites was a factor in their expansion and colonization of the pelagic zone and resulted in remarkable diversification of belemnites. Innovative traits of the embryonic shell of Sinemurian–Bajocian belemnites include: (1) an inorganic–organic primordial rostrum encapsulating the protoconch and the phragmocone, its non-biomineralized component, possibly chitin, is herein detected for the first time; (2) an organic rich closing membrane which was under formation. It was yet perforated and possessed a foramen; and (3) an organic rich pro-ostracum earlier documented in an embryonic shell of Pliensbachian Passaloteuthis. The inorganic–organic primordial rostrum tightly coating the protoconch and phragmocone supposedly enhanced protection, without increase in shell weight, of the Early Jurassic belemnites against explosion in deep water environment. This may have increased the depth and temperature ranges of hatching eggs, accelerated the adaptation of hatchlings to a nektonic mode of life andpromoted increasing diversity of belemnoids. This study supports the hypothesis thatbelemnite hatchlings were ‘a miniature of the adults’.
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| 7. |
- Doguzhaeva, Larisa, et al.
(författare)
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Evolutionary patterns of Carboniferous coleoid cephalopods based on their diversity and morphological plasticity
- 2010. - First
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Ingår i: <em>Cephalopods - Present and Past</em><em></em>. - Tokyo, Japan : Tokai University Press. ; , s. 171-180
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Bokkapitel (refereegranskat)abstract
- The morphological traits of the Carboniferous coleoids were analyzed to discover re-occurring combinations of different characteristic features during the early evolution of coleoid cephalopods. The early coleoid evolution in the Carboniferous is characterized by (1) a complex mosaic combination of the "old" and "new" morphological traits, (2) the parallel appearance and variations of new morphological features, and (3) relatively rapid changes in basic morphology. A mosaic combination is exemplified with Donovaniconus, which possesses a body chamber (bactritoid trait), a pro-ostracum-like structure (a novelty), and an ink sac (coleoid trait), or Mutveiconites, which combines a body chamber (bactritoid trait) and a rostrum (coleoid trait). A novelty or new feature can appear at any evolutionary stage, but "old" traits can continue to exist for a long period after the appearance of a novelty in another form. An example of this phenomenon is demonstrated by the evolutionary loss of the body chamber in the Lower Carboniferous (ca. 325 MY) taxon Hematites, which is the earliest recorded coleoid, and the retention of the body chamber in the Late Carboniferous (ca. 290 MY) taxa Shimanskya, Mutveiconites, Donovaniconus, and Saundersites. The parallel appearance of new morphological traits is illustrated by the appearance of the massive rostrum in the Early Carboniferous Hematites and the development of a cap-like small loosely calcified rostrum in the Late Carboniferous Mutveiconites.
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| 8. |
- Doguzhaeva, Larisa
(författare)
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Functional significance of parabolae, interpreted on the basis of shell morphology, ultrastructure and chemical analyses of the Callovian ammonite Indosphinctes (Ammonoidea: Perisphinctidae), Central Russia
- 2012
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Ingår i: Revue de Paléobiologie, Genève. - Genève. - 0253-6730. ; 11, s. 89-101
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Tidskriftsartikel (refereegranskat)abstract
- The parabola-bearing shells of the Callovian ammonite Indosphinctes (Elatmites) submutatus Nikitin from Ryazan Region, Central Russia, are examined using morphological, ultrastructural and chemical approaches to clarify the functional significance of the parabola.The parabolae are missing in the embryonic shell that is comparatively large (about 1.5 mm in diameter) and has a prismatic shell wall, with the exception of the nacreous primary varix. There are no parabolae at the early post-hatching stage at which the shell wall consists of the outer prismatic, middle nacreous and inner prismatic layers. The parabolae are observed in small and medium-sized shells (about 15-30 mm in diameter) in which the bulk of the lateral and ventral portions of the shell wall are formed by the nacreous layer, and the outer prismatic layer seems to be missing. The thin dorsal wall lacks the nacreous layer, and the adjacent whorls are connected via a structureless layer showing a nano-granular ultrastructure. Beyond the contact of the whorls, the broken rolled ends of this layer are only preserved at the corners between the neighboring whorls. This perishable layer contains N (an indicator of organic ingredient preserved), C, O, Mg, Ca, Fe, Zn, and Sr. The same elements are detected in the structureless shell material from repaired injuries of the shell wall. There are about seven parabolae in a whorl. The parabolae are commonly exhibited on the exposed dorsal wall when the next whorl is broken. The parabolae are also observed on the outer shell surface not yet covered with the dorsal wall of the next whorl. The body chamber is about 330° in spiral length. The paired adorally ‘opened’ parabolic ‘notches’ are expressed either as small knobs on internal moulds, as nodes on the dorsal wall, or as a contour reinforced with minor relief on outer surface of the body chamber. A parabolic node represents a lens-like inclusion into the nacreous layer of the shell wall and is composed of flattened, loosely packed spherulites and nacreous micro-chips. Based on these observations it is suggested that (1) the shell of I. (E.) submutatus, excepting earlyontogenetic stages, was coated with an organic-rich layer, possibly secreted from the outside like the outer plate in the shell wall of extant Spirula; (2) the parabolae served as attachment structures related to the mantle attachment inside and outside the body chamber.
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| 9. |
- Doguzhaeva, Larisa, et al.
(författare)
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Pro-ostraca of Triassic belemnoids (Cephalopoda) from Northern Calcareous Alps, with observations on their mode of preservation in an environment of northern Tethys which allowed for carbonization of non-biomineralized structures.
- 2012
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Ingår i: N. Jb. Geol. Paläont. Abh.. - Stuttgart : Schweizerbart. ; 266:1, s. 31-38
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Tidskriftsartikel (refereegranskat)abstract
- A pro-ostracum – the anterior dorsal plate subdivided into three longitudinal fields – isdeveloped in Triassic phragmoteuthids (Phragmoteuthis, Breviconoteuthis) and the belemnotheutid? (Lunzoteuthis) but is missing in aulacocerids which have a pro-ostracum-like structure – the dorsal apertural crest with arched growth lines. Two types of pro-ostraca: a Phragmoteuthis-type, characterized by arched growth lines in each field, and a Lunzoteuthis-type, in which the median field has arched growth lines and lateral fields bear converging longitudinal ridges, are distinguished. The pro-ostracum with the ridged lateral fields evidently obtained further rapid development; in the Sinemurian belemnite Nannobelus the ridged lateral fields are already formed by the longitudinally exposed narrow portions of succeeding, overlapping sublayers of the pro-ostracum. This structure apparently enabled efficient mantle/shell linkage that facilitated effective manoeuvring, an active mode of life and global radiation of Jurassic belemnites. Exceptional, large scale, preservation of pro-ostraca in lower Carnian of Schindelberg, Lower Austria, and Raibl, North Italy, was possibly due to the concurrency of (1) an environment of the northern Tethys that allowed for post-mortem carbon substitution of chitin and other non-biomineralized material, such as ink and mantle tissue, and (2) the inorganic-organic composition of pro-ostracum as indicated by micro-laminations typical of chitin-containing material and characterized by alteration of chitinous and carbonate laminas similar to those in cuttlebones of Recent Sepia.
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| 10. |
- Doguzhaeva, Larisa, et al.
(författare)
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Siphonal zone structure in the cuttlebone of Sepia officinalis
- 2015
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Ingår i: Swiss Journal of Palaeontology. - Springer Basal.
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Tidskriftsartikel (refereegranskat)abstract
- The evolutionary process through which the siphonal zone of the cuttlebone of Sepia replaced the tubular siphuncle seen in other shelled cephalopods is poorly understood. Recently, porous connecting stripes, interpreted as homologous to connecting rings of tubular siphuncles, were revealed in Sepia (Acanthosepion) cf. savignyi (Geobios, 45:13–17, 2012). New data on the siphonal zone structure are herein demonstrated through SEM testing of 16 beach-collected cuttlebones ofSepia officinalis from Vale do Lobo, southern Portugal. In examined cuttlebones, the organic connecting stripes are mineralized along their peripheries where they are attached to septa by inorganic–organic porous contacting ridges. The contacting ridges consist of globular crystalline units within an organic matrix; each globule is a stack of rounded alternating organic and mineralized microlaminas parallel to the septal surface; mineralized microlaminas contain carbonate microgranules. Porous connecting stripes together with the contacting ridges may serve as transport routes for the cameral liquid used in buoyancy regulation. The contacting ridges appear to reinforce contacts between the connecting stripes and septa, and may strengthen shell resistance to changing environments. Lamella–fibrillar nacre in septa is demonstrated in Sepia for the first time. Comparison of Sepia and Spirula reveals the common character of their phragmocones, the slit-like shape of the permeable zones between chambers and the siphuncle. Narrowing of the permeable zones may provide shell resistance to high hydrostatic pressure; however, the essentially dissimilar relative length of the permeable zones may results in different capabilities of two genera for buoyancy regulation. In Sepia, long narrow porous inorganic–organic permeable connecting stripes and contacting ridges may allow for rapid buoyancy regulation which would lead to environmental plasticity and higher species diversity.
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