Dan L. Danielopol | University of Graz (original) (raw)

Papers by Dan L. Danielopol

Most commonly used techniques for treating ostracod soft body for taxonomical purposes with optic... more Most commonly used techniques for treating ostracod soft body for taxonomical purposes with optical microscopy are described with emphasis on the order Podocopida. A variety of procedures for pre-treatment, storage, recovery of dried specimens, dissection, temporary and permanent mounting, and staining methods are presented and evaluated. General morphology and terminology of the ostracod appendages are also summarised.

Travaux de l'Institut de Speologie Emile Racovitza, 2012

A revised classification of Malacostraca based on a phylogenetic analysis is presented. For this ... more A revised classification of Malacostraca based on a phylogenetic analysis is presented. For this purpose 68 morphological characters were cladistically treated using the parsimony programme Paup 4.10. The system here proposed is a reflection of the cladistic tree produced by TABACARU & DANIELOPOL (2011). The following aspects are in the present contribution developed: (1) We consider, in accordance with a widely held opinion of carcinologists, that Phyllocarida (Ord. Leptostraca) displays essential synapomorphies with Malacostraca, namely tagmosis 5+7+8+telson, fixation of the gonopore on the 6 th female thoracic-segment and on the 8 th male-thoracic segment. Based on this assertion Phyllocarida belongs to the Class Malacostraca. Hence we do not share either the ancient view of H. MILNE EDWARDS (1840), who included Nebalia into the Ordo Phyllopodes, Legio Branchiopodes Latreille, or the more recent opinions of SCHRAM (1986), WHEELER (1997) and WILLS (1998) who consider Phyllocarida as belonging to Phyllopoda; (2) the Class Malacostraca is dichotomously separated into Subclasses, Phyllocarida and Eumalacostraca. This is due to the fact that Hoplocarida shares essential synapomorphies with the Eumalacostraca, namely loss of 7 th somite of the pleon, thoracic endopod built as stenopod and pleopods of the 6 th somite of pleon differentiated as uropods. This opinion is in contradiction with those of other carcinologists who, presupposing a distinct origin of Hoplocarida, consider the Class Malacostraca separated in three Subclasses:

Travaux de l'Institut de Speologie Emile Racovitza, 2018

Traian Orghidan aurait eu 100 ans cette année. Malheureusement il nous a quitté prématurément à l... more Traian Orghidan aurait eu 100 ans cette année. Malheureusement il nous a quitté prématurément à l'âge de 68 ans. Ce naturaliste d'une exceptionnelle valeur laisse des souvenirs particulièrement marquants pour ses amis et collaborateurs. Voici quelques réflexions, sur la personnalité de ce naturaliste et sur sa contribution scientifique, qui nous reviennent en mémoire après avoir eu le privilège de le connaître directement et de travailler dans les laboratoires qu'il a dirigés avec enthousiasme et beaucoup de tact. Nous retracerons ici deux volets de sa personnalité scientifique: le chercheur passionné pour la connaissance de la nature et l'organisateur dynamique de l'Institut de Spéologie qui après 1956 a permis une renaissance des recherches spéologiques en Roumanie. Ses qualités ont marqué aussi notre façon de voir la nature, surtout celle du monde souterrain, un milieu caléidoscopique fascinant.

Une analyse cladistique ayant pour but de reconstruire les relations phylogenetiques des principa... more Une analyse cladistique ayant pour but de reconstruire les relations phylogenetiques des principales lignees (sous-ordres) des Isopoda d'une part et les relations de ce dernier groupe avec d'autres ordres de Malacostraces d'autre part est presentee a partir d'une matrice de 75 et/ou 76 traits morphologiques. Certains de ces caracteres sont nouveaux, d'autres ont recu ici de nouvelles interpretations. La monophylie des Isopoda ressort de cette analyse en utilisant comme extra groupes les ordres des Amphipoda et des Tanaidacea. Les Tanaidacea representent le groupe frere des Isopoda. Les Phreatoicidea sont le groupe le plus primitif parmi les Isopoda. L'absence de la synapomorphie essentielle des Asellota, c'est-a-dire la conformation speciale de l'organe copulateur mâle, ainsi que la presence de remarquables autapomorphies, permettent de considerer les Microcerberides non pas comme une famille des Aselloidea, mais comme un sous-ordre, les Microcerberoi...

Acta Palaeontologica Polonica, 2020

Sieve-type normal pore canals (StPC) occur commonly in living and fossil cytheroid ostracods but ... more Sieve-type normal pore canals (StPC) occur commonly in living and fossil cytheroid ostracods but their biological function(s) and evolutionary history are poorly known. The new genus Minyocythere and its four species: Minyocythere macroporosa sp. nov., M. angulata sp. nov., M. maculosa, and M. tuberculata from the Middle Jurassic have StPC prominently developed, display a range of normal pore canals, and provide a context for review of the geological record and palaeobiological potential of these structures, and their application as a taxonomic tool compared with classical approaches. The related Cretaceous genus Dolocythere is reviewed and Dolocythere amphistiela sp. nov. described. The significance of StPC for comparative morphology, systematics, palaeobiology and environmental interpretation are discussed. The range of normal pore canals observed, including StPC, is greater than previously described and several types can occur on one animal implying different life functions. The potential of normal pore canals especially StPC for systematic use is established although good preservation is essential. The functional significance of normal pore canals and their setae must be verified with living material before their evolutionary history can be deduced and their application to palaeoenvironmental interpretation and modern environmental monitoring enhanced.

Joannea …, 2011

Leptocytheridae have a long historical documentation in Central Europe. They were found in the ma... more Leptocytheridae have a long historical documentation in Central Europe. They were found in the marine environment of the Paratethys during the Badenian-Sarmatian (Middle Miocene), and during the Late Miocene (Pannonian) in long-lived Lake Pannon. The modern systematics of this group changed from a taxonomy based on a single genus, Leptocythere SARS to several genera, Callistocythere RUGGIERI, Euxinocythere (STANCHEVA) and Amnicythere (DEVOTO). The assertion of taxa with certainty to these latter genera using classic methods of identification became difficult. The present communication compares several morphological characters of the carapace in order to find taxonomic criteria, which would allow a more secured identification of fossil leptocytherids for our research projects. Four morphological characters are presented: (1) the general shape of valves, analysed with classic methods of transmitted light microscopy and geometric morphometric techniques; (2) the morphology of the anterior inner lamella of the valve, also studied with transmitted light microscopy; (3) the hinge structure, mainly aspects of the left valve; (4) the external ornamentation of the valve. The latter two morphological characters were best observed in scanning electron microscopy. The morphological characters we analysed are complex entities, which display causal coherence, respectively quasi-independence when integrated within the framework of a whole organism. To gain more experience with fossil Amnicythere taxa we use information from a companion presentation (NAMIOTKO et al. 2011), which deals with details of the living species, A. karamani (KLIE) from Lake Ohrid. Additionally, we present morphological details of valves of several Recent Leptocythere and Callistocythere taxa from the Atlantic Ocean and the Mediterranean Sea. The fossil material used for this presentation comes from our own studies of the sites Hennersdorf (Middle Pannonian "E", cf. HARZ

Zootaxa, Jan 3, 2018

Examination of normal pore canals, especially sieve-type pore canals, in living and fossil repres... more Examination of normal pore canals, especially sieve-type pore canals, in living and fossil representatives of ten genera of the family Limnocytheridae, subfamily Timiriaseviinae, has revealed important diversity of structure. These complex pore canals have been studied via high-resolution scanning electron microscopy (the Cartographic Method) and analysed via the application of newly devised indices to assess patterns of consistency and variation in both detailed structure of individual pores and of their distribution on the calcified valve. The timiriaseviine taxa are compared with species of the genera Limnocythere, sub-family Limnocytherinae and Cyprideis (family Cytherideidae). The relationship between the living animal and its aquatic environment is discussed in the light of previous studies and of new evidence herein. The importance of normal pore canals for systematics is highlighted by the recognition and definition of the new tribe Gomphodellini Danielopol, Cabral Lord nov....

SIL Proceedings, 1922-2010, 1994

Our colleague and friend Dr. Radu Olteanu passed away in Bucharest on 18 December 2015. Radu was ... more Our colleague and friend Dr. Radu Olteanu passed away in Bucharest on 18 December 2015. Radu was one of the most gifted micropalaeontologist of his generation, who produced , during his scientific career, started in 1966 until present day , important information based on intensive work, in the field and laboratory, always motivated by deep conceptual thoughts. It is the extraordinary personality of a polymath that deserves to be remembered here. The cultural interests of Radu Olteanu covered a wide spectrum of topics related to general geology, palaeontology and evolutionary biology, as well as topics belonging to humanities, like philosophical aspects of human ethics, or those related to belles-lettres. Within the international community of ostracod researchers , the scientific reputation of Radu Olteanu is well established through a series of publications widely distributed. His taxonomic investigations were, mainly, related to questions dealing with biostratigraphy or with palaeo...

Vie Et Milieu, 2000

La diversite taxinomique de la faune des Cyclopoides (23 especes, 10 hypogees, 13 epigees) habita... more La diversite taxinomique de la faune des Cyclopoides (23 especes, 10 hypogees, 13 epigees) habitant la nappe phreatique du Lobau dans un perimetre d'environ 0.8 km- de la plaine alluviale du Danube a Vienne, est analysee au niveau de plusieurs echelles metriques. Ces informations sont comparees avec des donnees obtenues dans deux autres localites, Regelsbrunn et Deutsch-Wagram, situees a 16 km du Lobau. L'activite motrice differente de plusieurs Cyclopoides hypoges pendant la recherche du substrat et de la nourriture potentielle documente le probleme de la diversite ecologique chez les Cyclopoides souterrains de la plaine alluviale du Danube. L'origine et la diversite potentielle des Cyclopoides hypoges de la zone etudiee est discutee a partir d'arguments d'ordre statistique, ecologique, biogeographique et de la biologie evolutive.

Vie Et Milieu, 2002

Les Cyclopoides peuplant le Parc National « Prairies du Danube » ont une diversite taxonomique im... more Les Cyclopoides peuplant le Parc National « Prairies du Danube » ont une diversite taxonomique importante par rapport a la faune regionale totale. L'etude comparative des communautes peuplant deux sites, Untere Lobau et Regelsbrunner Au, d'une surface d'environ 0,8 Km 2 chacun, dans le Parc National, montre que le premier presente une diversite taxonomique importante: il se distingue par des valeurs elevees de l'index de la distinction taxonomique moyenne (average taxonomic distinctness - AvTD) ainsi que par le nombre des genres ayant un nombre reduit d'especes (le type G 1/2 ). Le Untere Lobau est un site a diversite exceptionnelle (hotspot diversity site) tenant compte de la diversite taxonomique importante des Cyclopoides recenses dans les eaux souterraines de ce perimetre. La fraction hypogee des assemblages des Cyclopoides des deux sites, Untere Lobau et Regelsbrunner Au, presentent des valeurs plus faibles pour l'indice de la distinction taxonomique moyenne et des valeurs plus importantes de la variance de la distinction taxonomique (Variance of taxonomic distinctness - VarTD), par rapport a celles de la communaute d'origine. La faune des Cyclopoides de ce Parc National, ayant une diversite taxonomique exceptionnelle, confirme l'interet ecologique et culturel porte en Autriche pour la conservation de cette region naturelle du Danube.

Abstract. The history of life is the chronicle of diversification. Each taxonomic group originate... more Abstract. The history of life is the chronicle of diversification. Each taxonomic group originates from a single ancestor and diversifies into a number of species. The evolutionary process, with its two major components (speciation and extinction), is the force working behind. Several models, i.e. explicit mathematical statements of a hypothesis, have been developed in order to inspect the likely output of the evolutionary process and to compare it with actual diversity patterns observed in Nature. The British statistician George Udny Yule produced one of the earliest attempts of such models, now known as the Yule Process, which leads to the Yule-Simon Distribution. His model and the aforementioned probability distribution belong, as well as the Zeta Distribution used in this contribution, to the large family of Power Laws. It focuses on the distribution of the size (= number of species) of genera within a taxonomic group. Here, the data of the nonmarine ostracod family Candoninae a...

Species concepts represent one of the "hot" topics of the current evolutionary biology.... more Species concepts represent one of the "hot" topics of the current evolutionary biology. The Romanian natural scientists EMIL G. RACOVITZA and NICOLAE BOTNARIUC defined animal species in different ways: EMIL G. RACOVITZA supported a Genealogic species concept, expressed as "a colony of isolated consanguines". The RACOVITZA's concept considers species as homogenous lineages of organisms which evolve during their history. Description of such entities requires the recognition of primitive and derived states of the morphologic traits. Hence EMIL G. RACOVITZA's ideas preceded the principles of phylogenetic systematics of WILLY HENNIG and his followers. Geographic isolation is viewed by RACOVITZA as one of the main drivers of the speciation process. NICOLAE BOTNARIUC developed an innovative Systems-species concept where quasi- independent organisms through their relationships within populations build a supraindividual system. The integrative properties of the po...

Soceni is an important fossiliferous site in Central Europe which documents the Middle Miocene de... more Soceni is an important fossiliferous site in Central Europe which documents the Middle Miocene development of the Central Paratethys Sea and the formation of Lake Pannon during the Late Miocene. The site is especially famous due to the palaeontological study on molluscs by Erich Jekelius during 1930‐1940. A visit to Soceni in 2006 allowed us to examine Sarmatian and Pannonian sediments and collect fossil material. We remained impressed by Erich Jekelius’ work and here we briefly present the scientific personality and achievements of this extraordinary geologist. We will explain why Jekelius investigations at Soceni are still valuable for the ongoing palaeontological research nowadays.

The Recent ostracod species Manawa staceyi Swanson, 1989, belonging to the superfamily Puncioidea... more The Recent ostracod species Manawa staceyi Swanson, 1989, belonging to the superfamily Puncioidea, was originally considered a relict species related to the Palaeozoic Palaeocopa, ostracods, now extinct. During the last 30 years research on Manawa documented the basal position of the superfamily Puncioidea within the phylogenetic tree of the Subclass Podocopa. The Palaeocopa is possibly a heterogenous taxon containing both myodocopids and podocopids. Re-examination of the systematic position, phylogenetic affinities and evolution of the superfamily Puncioidea is presented using information from the comparative analysis of the body plans of Myodocopa and Podocopa, rationalised within morpho-functional modules: the carapace as a‘protective’ construct, the ambulatory complex, combined with feeding, reproductive and sensory systems. The significant traits of the different morpho-functional modules of the superfamily Puncioidea when compared to those of the ostracod Orders Podocopida and...

Vie Et Milieu, 1988

Description de la morphologie des individus vivants dans le Seebach (ruisseau alpin de Basse Autr... more Description de la morphologie des individus vivants dans le Seebach (ruisseau alpin de Basse Autriche). Repartition spatiale de l'espece, repartition verticale dans les sediments. Adaptations morphologiques au milieu intestitiel

International Review of Hydrobiology, 1999