WorldCat Identities

Ahlberg, Per Erik 1963-

Overview
Works: 32 works in 53 publications in 3 languages and 1,053 library holdings
Genres: Documentary films  Science films  Documentary television programs  Science television programs  Television mini-series  Educational films  History  Juvenile works  Children's films  Nonfiction films 
Roles: osp, Author, Editor, Narrator, 958
Publication Timeline
.
Most widely held works by Per Erik Ahlberg
Major events in early vertebrate evolution : palaeontology, phylogeny, genetics, and development by Per Erik Ahlberg( )

12 editions published between 2001 and 2003 in English and held by 634 WorldCat member libraries worldwide

Demonstrates how phylogenetics and developmental biology can provide complementary and mutually supportive information about evolutionary events which have had a significant impact on life on this planet, e.g. the origin of jaws and fins
Miracle planet( Visual )

3 editions published in 2005 in English and held by 323 WorldCat member libraries worldwide

A five-part series recounting the earth's 4 billion-year evolution and the origin and evolution of life
Localities, distribution and stratigraphical context of the Late Devonian tetrapods of East Greenland by Henning Blom( Book )

4 editions published in 2005 in English and held by 38 WorldCat member libraries worldwide

Major events in early vertebrate evolution : palaeontology, phylogeny, genetics and development( Book )

1 edition published in 2001 in English and held by 19 WorldCat member libraries worldwide

Major events in early vertebrate evolution by Per Erik Ahlberg( Book )

3 editions published between 2000 and 2002 in English and held by 8 WorldCat member libraries worldwide

Demonstrates how phylogenetics and developmental biology can provide complementary and mutually supportive information about evolutionary events which have had a significant impact on life on this planet, e.g. the origin of jaws and fins
The anatomy and phylogeny of porolepiform fishes, with special reference to glytplepis by Per Erik Ahlberg( Book )

3 editions published in 1989 in English and held by 5 WorldCat member libraries worldwide

Animated life series( Visual )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

"These five short films, produced in conjunction with The New York Times, bring to life five historical scientific discoveries and the people behind them: Alfred Russel Wallace and his contribution to the concept of natural selection; Antonie van Leeuwenhoek's microscope; Alfred Wegener and the idea of continental drift; Mary Leakey and the Laetoli footprints; and Marjorie Courtenay Latimer's discovery of the coelacanth "fossil fish."--Publisher
Localities, distribution and stratigraphical context of the Late Devonian tetrapods of East Greenland by Henning Blom( Book )

1 edition published in 2005 in English and held by 2 WorldCat member libraries worldwide

Na tropach praczworonoga w Górach Świętokrzyskich = In the Holy Cross Mountains on the tracks of the early tetrapods by Grzegorz Niedźwiedzki( Book )

1 edition published in 2011 in Polish and held by 2 WorldCat member libraries worldwide

Scales and Tooth Whorls of Ancient Fishes Challenge Distinction between External and Oral 'Teeth' by Qingming Qu( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

The debate about the origin of the vertebrate dentition has been given fresh fuel by new fossil discoveries and developmental studies of extant animals. Odontodes (teeth or tooth-like structures) can be found in two distinct regions, the 'internal' oropharyngeal cavity and the 'external' skin. A recent hypothesis argues that regularly patterned odontodes is a specific oropharyngeal feature, whereas odontodes in the external skeleton lack this organization. However, this argument relies on the skeletal system of modern chondrichthyans (sharks and their relatives), which differ from other gnathostome (jawed vertebrate) groups in not having dermal bones associated with the odontodes. Their external skeleton is also composed of monoodontode 'placoid scales', whereas the scales of most early fossil gnathostomes are polyodontode, i.e. constructed from several odontodes on a shared bony base. Propagation phase contrast X-ray Synchrotron microtomography (PPC-SRmCT) is used to study the polyodontode scales of the early bony fish Andreolepis hedei. The odontodes constructing a single scale are reconstructed in 3D, and a linear and regular growth mechanism similar to that in a gnathostome dentition is confirmed, together with a second, gap-filling growth mechanism. Acanthodian tooth whorls are described, which show that ossification of the whorl base preceded and probably patterned the development of the dental lamina, in contrast to the condition in sharks where the dental lamina develops early and patterns the dentition. The new findings reveal, for the first time, how polyodontode scales grow in 3D in an extinct bony fish. They show that dentition-like odontode patterning occurs on scales and that the primary patterning unit of a tooth whorl may be the bony base rather than the odontodes it carries. These results contradict the hypothesis that oropharyngeal and external odontode skeletons are fundamentally separate and suggest that the importance of dermal bone interactions to odontode patterning has been underestimated
The origin of the internal nostril of tetrapods by Min Zhu( )

1 edition published in 2004 in English and held by 1 WorldCat member library worldwide

Major events in vertebrate evolution palaeontology, phylogeny, genetics and development by Per Erik Ahlberg( Book )

1 edition published in 2001 in English and held by 1 WorldCat member library worldwide

Ventastega curonica and the origin of tetrapod morphology( )

1 edition published in 2008 in English and held by 1 WorldCat member library worldwide

Etudes anatomiques des genres Porolepis Woodward 1891 et Heimenia Ørvig 1969 ('Porolepididae', Sarcopterygii) et du genre Powichthys Jessen 1975 (Powichthyidae, Sarcopterygii) du Dévonien inférieur et moyen du Spitzberg - Phylogénie des Dipnomorpha by G Clément( Book )

1 edition published in 2001 in French and held by 1 WorldCat member library worldwide

Les 'Porolepididae' et les Powichthyidae sont des Vertébrés Sarcoptérygiens non Tétrapodes. Ces deux groupes fossiles sont exclusivement dévoniens (Paléozoïque moyen) et font partie des Sarcoptérygiens les plus anciens. Les connaissances sur l'anatomie des 'Porolepididae' sont complétées grâce à un matériel inédit et relativement complet de l'espèce Heimenia ensis, auparavant uniquement connue par des écailles isolées. Ce matériel, d'une excellente préservation, provient de l'Emsien-Eifelien (Dévonien inférieur et moyen) du Spitzberg. Les Powichthyidae n'étaient pas connus que par une seule espèce, Powichthys thorsteinssoni, du Lochkovien-Praguien (Dévonien inférieur) du Canada arctique. Le nouveau matériel du Praguien du Spitzberg apporte des connaissances inédites sur l'anatomie du crâne, des éléments dermiques du plafond buccal, sur le postorbitaire et sur les écailles. L'exceptionnelle préservation, chez ces deux espèces, d'éléments dermiques délimitant une présupposée choane. Il ressort de cette étude que les choanes étaient absentes chez les Porolépiformes et les Powichthyidae. Les descriptions de chaque complexe anatomique de ces deux espèces, Heimenia ensis et Powichthys sp., sont suivies d'une comparaison avec les autres Dipnomorpha (les Dipneustes dévoniens et les genres Youngolepis et Daibolepis). La systématique des 'Porolepididae' est clarifiée et les positions phylogénétiques des taxons Heimenia et Powichthys au sein des Dipnomorpha sont discutées après une analyse cladistique
Vascularization and odontode structure of a dorsal ridge spine of Romundina stellina Ørvig 1975 by Anna Jerve( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

There are two types of dermal skeletons in jawed vertebrates: placoderms and osteichthyans carry large bony plates (macromery), whereas chondrichthyans and acanthodians are covered by small scales (micromery). Fin spines are one of the last large dermal structures found on micromeric taxa and offer a potential source of histology and morphology that can be compared to those found on macromeric groups. Dermal fin spines offer a variety of morphology but aspects of their growth modes and homology are unclear. Here, we provide detailed descriptions of the microstructure and growth of a dorsal ridge spine from the acanthothoracid placoderm, Romundina stellina, using virtual three-dimensional paleohistological datasets. From these data we identify several layers of dentine ornamentation covering the lateral surfaces of the spine and reconstructed their growth pattern. We show that this spine likely grew posteriorly and proximally from a narrow portion of bone located along the leading edge of the spine. The spine is similarly constructed to the scales with a few exceptions, including the absence of polarized fibers distributed throughout the bone and the presence of a thin layer of perichondral bone. The composition of the spine (semidentine odontodes, dermal bone, perichondral bone) is identical to that of the Romundina dermal plates. These results illustrate the similarities and differences between the dermal tissues in Romundina and indicate that the spine grew differently from the dentinous fin spines from extant and fossil chondrichthyans. The morphology and histology of Romundina is most similar to the fin spine of the probable stem osteichthyan Lophosteus, with a well-developed inner cellular bony base and star-shaped odontodes on the surface. Results from these studies will undoubtedly have impact on our understanding of fossil fin spine histology and evolution, contributing to the on-going revision of early gnathostome phylogeny
Did terrestrial diversification of amoebas (Amoebozoa) occur in synchrony with land plants? by Omar Fiz-Palacios( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Evolution of lineage diversification through time is an active area of research where much progress has been made in the last decade. Contrary to the situation in animals and plants little is known about how diversification rates have evolved in most major groups of protist. This is mainly due to uncertainty about phylogenetic relationships, scarcity of the protist fossil record and the unknown diversity within these lineages. We have analyzed the evolutionary history of the supergroup Amoebozoa over the last 1000 million years using molecular dating and species number estimates. After an origin in the marine environment we have dated the colonization of terrestrial habitats by three distinct lineages of Amoebozoa: Dictyostelia, Myxogastria and Arcellinida. The common ancestor of the two sister taxa, Dictyostelia and Myxogastria, appears to have existed before the colonization of land by plants. In contrast Arcellinida seems to have diversify in synchrony with land plant radiation, and more specifically with that of mosses. Detection of acceleration of diversification rates in Myxogastria and Arcellinida points to a co-evolution within the terrestrial habitats, where land plants and the amoebozoans may have interacted during the evolution of these new ecosystems
Comparative pelvic development of the axolotl (Ambystoma mexicanum) and the Australian lungfish (Neoceratodus forsteri) conservation and innovation across the fish-tetrapod transition by Catherine Anne Boisvert( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Background: The fish-tetrapod transition was one of the major events in vertebrate evolution and was enabled by many morphological changes. Although the transformation of paired fish fins into tetrapod limbs has been a major topic of study in recent years, both from paleontological and comparative developmental perspectives, the interest has focused almost exclusively on the distal part of the appendage and in particular the origin of digits. Relatively little attention has been paid to the transformation of the pelvic girdle from a small unipartite structure to a large tripartite weight-bearing structure, allowing tetrapods to rely mostly on their hindlimbs for locomotion. In order to understand how the ischium and the ilium evolved and how the acetabulum was reoriented during this transition, growth series of the Australian lungfish Neoceratodus forsteri and the Mexican axolotl Ambystoma mexicanum were cleared and stained for cartilage and bone and immunostained for skeletal muscles. In order to understand the myological developmental data, hypotheses about the homologies of pelvic muscles in adults of Latimeria, Neoceratodus and Necturus were formulated based on descriptions from the literature of the coelacanth (Latimeria), the Australian Lungfish (Neoceratodus) and a salamander (Necturus). Results: In the axolotl and the lungfish, the chondrification of the pelvic girdle starts at the acetabula and progresses anteriorly in the lungfish and anteriorly and posteriorly in the salamander. The ilium develops by extending dorsally to meet and connect to the sacral rib in the axolotl. Homologous muscles develop in the same order with the hypaxial musculature developing first, followed by the deep, then the superficial pelvic musculature. Conclusions: Development of the pelvic endoskeleton and musculature is very similar in Neoceratodus and Ambystoma. If the acetabulum is seen as being a fixed landmark, the evolution of the ischium only required pubic pre-chondrogenic cells to migrate posteriorly. It is hypothesized that the iliac process or ridge present in most tetrapodomorph fish is the precursor to the tetrapod ilium and that its evolution mimicked its development in modern salamanders
Rapid braincase evolution between Panderichthys and the earliest tetrapods by Per Erik Ahlberg( Book )

1 edition published in 1996 in English and held by 1 WorldCat member library worldwide

Elginerpeton pancheni and the earliest tetrapod clade by Per Erik Ahlberg( Book )

1 edition published in 1995 in English and held by 1 WorldCat member library worldwide

Forty years of early vertebrates papers by International Symposium on Early and Lower Vertebrates( Book )

1 edition published in 2009 in English and held by 1 WorldCat member library worldwide

 
moreShow More Titles
fewerShow Fewer Titles
Audience Level
0
Audience Level
1
  Kids General Special  
Audience level: 0.28 (from 0.08 for Major even ... to 0.99 for The origin ...)

Major events in early vertebrate evolution : palaeontology, phylogeny, genetics, and development Major events in early vertebrate evolution : palaeontology, phylogeny, genetics and development Major events in early vertebrate evolution Major events in vertebrate evolution palaeontology, phylogeny, genetics and development
Covers
Major events in early vertebrate evolution : palaeontology, phylogeny, genetics and developmentMajor events in early vertebrate evolutionMajor events in vertebrate evolution palaeontology, phylogeny, genetics and development
Alternative Names
Ahlberg, Per

Ahlberg, Per E. 1963-

Per Ahlberg szwedzki paleontolog

Per E. Ahlberg paleontólogo sueco

Per E. Ahlberg Swedish paleontologist

Per E. Ahlberg Zweeds paleontoloog

Languages
English (38)

Polish (1)

French (1)