Michael Laaß

Verified

Michael verified their affiliation via an institutional email.

Learn more

Verified

Michael verified their affiliation via an institutional email.

Learn more

• Diplom
• PhD Student at TU Bergakademie Freiberg

The nasal region of the fossorial anomodont Kawingasaurus fossilis was virtually reconstructed from neutron-computed tomographic data and compared with the terrestrial species Pristerodon mackayi and other nonmammalian synapsids. The tomography of the Kawingasaurus skull reveals a pattern of maxillo-, naso-, fronto- and ethmoturbinal ridges that st...

Endophytic oviposition, the reproductive behavior of insects to insert eggs into dead or living plant tissue, and exophytic oviposition, the deposition of eggs on plants, are only rarely documented from the Pennsylvanian. In the present paper, ten oviposition types from the Piesberg quarry near Osnabrück, Germany (Osnabrück Formation, Middle Pennsy...

The origin of tympanic hearing in early synapsids is still controversial, because little is known about their inner ear and the function of their sound conducting apparatus. Here I describe probably the earliest tympanic ear in the synapsid lineage, the ear of Pristerodon (Therapsida, Anomodontia) from the Late Permian of South Africa, which was vi...

The special sensory, motor, and cognitive capabilities of mammals mainly depend upon the neocortex, which is the six-layered cover of the mammalian forebrain. The origin of the neocortex is still controversial and the current view is that larger brains with neocortex first evolved in late Triassic Mammaliaformes. Here, we report the earliest eviden...

Arthropod borings are commonly described from pteridophyte and gymnosperm wood in the late Palaeozoic, but they are almost unknown from calamitalean stems. In this paper, a new type of boring in calamitalean stems from two German localities is reported. These are the mine dumps of Plötz near Halle (Saale), Saale Basin, (Wettin Subformation, Latest...

The reconstruction of the mammalian nasal cavity is provided, showing respiratory and olfactory turbinates, which play a crucial role in the respiratory airflow conditioning and olfaction. The presence of turbinates in the nasal cavities of mammalian forerunners is still controversial due to the low fossilization potential of the turbinates. Howeve...

The evolutionary success of the Holometabola was primarily related to drastic changes in body structures between larvae, pupae and adults. This enabled the Holometabola to exploit a wide range of habitats during different ontogenetic stages. A unique adaptation of tiny, grub-like holometabolous larvae is leaf mining, which provides access to inner...

The book "Die Rotliegend-Fauna des Thüringer Waldes" was published in April 2024 as a special publication by Semana in A4 format by the Natural History Museum Schleusingen (editors: Ralf Werneburg and Joerg W. Schneider). 18 authors present the fauna of the Upper Carboniferous and Lower Permian of the Thuringian Forest Basin (Germany) in 19 chapter...

In the last years, the Piesberg quarry became one of the most important fossil Lagerstätten of Middle Pennsylvanian insects. Nevertheless, bearing in mind the vast material provided here, little is known about relations between arthropods and plants. Intensive collecting revealed a range of plant-arthropod interactions. As a result, at least 14 dam...

Infolded dentine (plicidentine) around the pulp cavities of the tooth roots is an ancient dental feature of fishes (sarcopterygians and actinopterygians) and several basal tetrapod groups. But, plicidentine is completely unknown in synapsids except some sphenacodontid pelycosaurs. An investigation of a skull of Varanosaurus acutirostris (Synapsida,...

Hitherto, plant-arthropod interactions have been rarely reported from the late Pennsylvanian (Gzhelian, Stephanian C) of the Saale Basin (Saxony Anhalt, Germany). A re-examination of material from the collections of the Martin-Luther-University Halle-Wittenberg and private collections revealed the presence of different damage types on plants. Among...

The Late Palaeozoic fossil record of plant-insect interactions contains few records of oviposition. Here we report the earliest evidence of exophytic oviposition, where eggs are laid directly on the outer surface of plants. The fossil structures consist of small, circular impressions on plant fossils from the late Pennsylvanian (Gzhelian, Stephania...

Paleontological exploration has a long history in Argentina. The rich and diverse Argentinian fossil record has proven to be of upmost importance, profusely contributing to the resolution of important evolutionary interrogations. The technological advances, in particular those regarding three-dimensional tomographic imaging, opened a new field of r...

Pelycosaurs are the most primitive members of the Synapsida, which is the clade that includes mammals. Consequently, pelycosaurs are of special interest with respect to our early evolution. We investigated a skull of Varanosaurus acustirostris for the first time by means of neutron tomography at the facility ANTARES at FRM II in Munich. Varanosauru...

Neutron Imaging is ideally suited for applications in cultural heritage even at small reactors with moderate image resolution. However, recently, high resolution imaging is being increasingly used for advanced studies, especially in paleontology. The special contrast for hydrogen and between neighboring elements in the periodic system allows for ne...

Only little is known about the brain antomy of the mammalian forerunners, the non-mammalian therapsids, because the brain reconstruction is faced with several problems. The first is that soft-tissue is not preserved. Consequently, information about the shape of the brain can only be deduced from the surrounding bony cavity. A second problem is that...

As having evolved on the stem line of mammals, the taxonomy and phylogeny of therapsids (Synapsida) are of special interest with respect to early mammalian evolution. Due to the fact that in most cases soft tissue of fossil vertebrates is not preserved, species can only be distinguished by diagnosis of morphological features of the skeleton. Moreov...

Most nonmammalian synapsids possess a mid-dorsal depression in the brain cavity known as the “unossified zone.” It remains obscure which structures this zone contained, and, as candidates, the vermis of the cerebellum, the superior sagittal sinus, a junction of several blood vessels, the pineal gland or other midbrain structures were considered. Ne...

Non-destructive imaging techniques can be extremely useful tools for the investigation and the assessment of palaeontological objects, as mechanical preparation of rare and valuable fossils is precluded in most cases. However, palaeontologists are often faced with the problem of choosing a method among a wide range of available techniques. In this...

There is a rich fossil record on plant-insect interactions from the late Palaeozoic. The majority were feeding traces on plants. In contrast, ovipositional traces have only been rarely reported. The earliest evidence of endophytic oviposition comes from the Late Carboniferous (Stefanian) of the Graissessac Basin of France and the Saale Basin of Ger...

One of the most distinctive mammalian features are the turbinal bones. There are several types of turbinal bones differing as to function and position in the nasal cavity: The naso- and ethmoturbinals are situated apart from the main respiratory airflow and are usually protected by a transverse lamina and covered with an olfactory epithelium. The t...

From the Mid-Permian to the Triassic the anomodonts were the most successful herbivores on land. As they belong to the therapsids, which were the forerunners of mammals, they are of special interest with respect to early mammalian evolution. Diictodon feliceps was one of the most common anomodonts from the Late Permian of South Africa. In the past,...

The special sensory, motor and cognitive capabilities of mammals mainly depend upon the neocortex, which is the six-layered cover of the mammalian forebrain. The origin of the neocortex is still controversial and the current view is that larger brains with neocortex firstly evolved in Late Triassic mammaliaformes (Rowe et al. 2011). We reconstructe...

Xiphosurans from the Mesozoic (Limulacea, “limulids”) are rare in the fossil record. Therefore, mechanical preparation is often precluded. Several non-destructive methods for investigations of these fossils are now available. A comparison is presented between two different techniques, x-ray computed tomography (CT) and computed laminography (CL). T...

The internal cranial structure of mammalian ancestors, i.e. the therapsids or “mammal-like reptiles”, is crucial for understanding the early mammalian evolution. In the past therapsid skulls were investigated by mechanical sectioning or serial grinding, which was a very time-consuming and destructive process and could only be applied to non-valuabl...

The cranial endocast of Pristerodon mackayi is described, which has been virtually reconstructed on the basis of neutron tomographic data. The gross anatomy of the cranial endocast of Pristerodon resembles other nonmammalian synapsids such as Thrinaxodon liorhinus in having a narrow, tubular forebrain, well developed olfactory bulbs, a large pariet...

An investigation of the internal cranial anatomy of the anomodont Kawingasaurus from the Upper Permian Usili Formation in Tanzania by means of neutron tomography revealed an unusual inner and middle ear anatomy such as extraordinarily inflated vestibules, lateroventrally orientated stapes with large footplates, and a small angle between the planes...

The reproductive strategy of insects of inserting eggs into plant tissue (endophytic oviposition) is known from the Late Carboniferous onwards. The earliest known ovipositional scars are large, that is up to 38 mm long, and irregular both in size and in shape, and they are not arranged in a regular pattern. Oviposition patterns resembling those of...

Since palaeontology exists scientists were keen to reconstruct extinct animals, their locomotion, behaviour and living environment from the fossil record. The earliest reconstructions consisted of simple sketches, paintings or physical models. Today it is possible to create digital 3D models of extinct animals. These can be generated either by geod...

Fossils in situ provide useful stratigraphical and taphonomical information, which helps to reconstruct palaeoenvironments and-ecosystems. This information gets lost as soon as the fossils are excavated, unless the site has been documented in detail before. A detailed documentation of palaeontological sites is also very helpful for preparation and...

The internal structure of fossils reveals key information about anatomy, palaeobiology and phylogeny of extinct taxa. Thus, many fossils have been sectioned serially or investigated by grinding techniques. Because these methods are destructive, they have mostly been applied to non-valuable or poorly preserved specimens. Moreover, they are very time...

Laaß, M., Hampe, O., Schudack, M., Hoff, C., Kardjilov, N. and Hilger A. (2010). New insights into the respiration and metabolic physiology of Lystrosaurus. —Acta Zoologica (Stockholm) 92: 363–371. The first examination by neutron tomography of a skull of Lystrosaurus declivis (Therapsida, Anomodontia) from the Lower Triassic of South Africa showed...

The Grabfeld Formation represents the basinal facies of the lowermost Middle Keuper Subgroup of the Keuper Group. The formation consists almost completely of nonmarine dolomitic mudstones and evaporites, intercalated by many, but thin, dolomite beds, partly of marine but mostly of lacustrine facies. The thickness ranges from about 60 m near the Swi...