Ronny Maik Leder

Paleontology is an interdisciplinary field that attracts all walks of life, from hobbyists to professionals. This shared interest between the public and professional communities offers ample opportunities for both collaboration and conflict. In order to facilitate collaborations and minimize conflict, it is necessary for all stakeholders to understand what motivates this passion and to establish a set of best practices based upon their respective impetus. A primary goal of the NSF-funded FOSSIL Project is to establish a unified community of paleontologists and promote said best practices. Adoption of these best practices further serves to meet the goals of the partnering NSF-funded project, iDigBio, which aims to digitize all national and international natural history collections. The FOSSIL Project PaleoBlitz was a pilot effort to better understand what motivates people’s passion for paleontology, while educating the public about best practices employed during the museum curatorial process. A diverse group of amateur paleontologists were selected based upon an application dispersed to fossil organizations throughout the United States. Post- and delayed- surveys were administered to analyze personal identity in relation to the practice of paleontology, determine acceptance of best practices, and refine the PaleoBlitz design. Herein, the results of this pilot study are summarized in an effort to encourage similar outreach events and provide a framework for successful implementation

Since the first time a Megalodon shark tooth was found and identified as such, the question of the actual size of one of the Neogene top predators was the subject of imaginative speculation and scientific investigation. Both the results and the methods that are used to determine the size led to enormous dimensions in each case but are still quite diverse and bear a high potential for uncertainty. The problem with the recently most used estimation methods like those from Gottfried (1996) and Shimada (2002) is that they make body length estimates based on isolated teeth rather than entire dentitions. After testing the validity of the body length estimates from Shimada, which is the most accepted at the moment, by using several associated dentitions from C. megalodon, we noticed an extreme variability of the body length estimates depending on the tooth position in the jaw (Perez et al, 2016). In fact, especially estimates from lateral teeth were extremely variable and estimates from posterior teeth also varied significantly. The circumstance that we have this huge range in estimates makes it obvious that the teeth proportions of Megalodon don't correlate with that of the living Great White Shark. Subject of the studies presented in this poster is the use of the sum of the crown width of teeth from associated tooth sets as a measure for the related width of the entire jaw. Then we use this relation for a body length estimate based on the jaw proportions derived from appropriate data from modern Great White sharks and Makos. Moreover, this study is a positive example of successful collaboration between professional and amateur paleontologists, one of the priorities of the NSF funded FOSSIL project. LEDER, Ronny M., Florida Museum of Natural History, Vertebrate Paleontology Department, Dickinson Hall, 1659 Museum Rd., PO Box 117800, Gainesville, FL 32611, PEREZ, Victor J., Geological Sciences, University of Florida, Gainesville, FL 32611 and BADAUT, Teddy, Independent affiliate, Thoirette, 39530 / 39240, France, leder.ronnymaik@flmnh.ufl.edu

Die morphologische Variabilität dentaler Strukturen, bei Haien der Familie der Carcharhinidae, ist sowohl innerhalb als auch zwischen den Arten unzureichend erforscht. Ohne Kenntnis der artspezifischen Parameter ist eine genaue taxonomische Klassifizierung von fossilen Haien anhand der Zähne jedoch unmöglich. Die umfassende Analyse der dentalen Strukturen rezenter carcharhinider Haie nach artspezifischen Merkmalen wurde genutzt, um die Ergebnisse auf die nächsten fossilen Verwandten zu übertragen. Besonderes Augenmerk galt darüber hinaus dem morphologischen Vergleich fossiler Zähne westatlantischer und zentralasiatischer Herkunft. Es wurde ein morphometrisches Analyseverfahren entwickelt, dass entgegen bestehender Methoden, gänzlich auf manuelle Datengewinnung verzichtet. Für die neue Methode der automatisierten algorithmischen Morphometrie (AAM) wurden erstmals, anhand von 2340 Einzelzähnen von 112 Individuen aus 41 Arten rezenter Carcharhinidae, die wesentlichen artspezifischen Me...

Paleontology is an interdisciplinary field that attracts all walks of life, from hobbyists to professionals. This shared interest between the public and professional communities offers ample opportunities for both collaboration and conflict. In order to facilitate collaborations and minimize conflict, it is necessary for all stakeholders to understand what motivates this passion and to establish a set of best practices based upon their respective impetus. A primary goal of the NSF-funded FOSSIL Project is to establish a unified community of paleontologists and promote said best practices. Adoption of these best practices further serves to meet the goals of the partnering NSF-funded project, iDigBio, which aims to digitize all national and international natural history collections. The FOSSIL Project PaleoBlitz was a pilot effort to better understand what motivates people’s passion for paleontology, while educating the public about best practices employed during the museum curatorial process. A diverse group of amateur paleontologists were selected based upon an application dispersed to fossil organizations throughout the United States. Post- and delayed- surveys were administered to analyze personal identity in relation to the practice of paleontology, determine acceptance of best practices, and refine the PaleoBlitz design. Herein, the results of this pilot study are summarized in an effort to encourage similar outreach events and provide a framework for successful implementation. LEDER, Ronny M.1, PEREZ, Victor J.2, LUNDGREN, Lisa M.3, ELLIS, Shari2 and DUNCKEL, Betty A.4, (1)Florida Museum of Natural History, Vertebrate Paleontology Department, Dickinson Hall, 1659 Museum Rd., PO Box 117800, Gainesville, FL 32611, (2)Geological Sciences, University of Florida, Gainesville, FL 32611,(3)College of Education, School of Teaching and Learning, University of Florida, 2403 Norman Hall, PO Box 117048, Gainesville, FL 32608, (4)Florida Museum of Natural History, University of Florida, PO Box 117800, Gainesville, FL 32611, victorjperez@ufl.edu

Since the first time a Megalodon shark tooth was found and identified as such, the question of the actual size of one of the Neogene top predators was the subject of imaginative speculation and scientific investigation. Both the results and the methods that are used to determine the size led to enormous dimensions in each case but are still quite diverse and bear a high potential for uncertainty. The problem with the recently most used estimation methods like those from Gottfried (1996) and Shimada (2002) is that they make body length estimates based on isolated teeth rather than entire dentitions. After testing the validity of the body length estimates from Shimada, which is the most accepted at the moment, by using several associated dentitions from C. megalodon, we noticed an extreme variability of the body length estimates depending on the tooth position in the jaw (Perez et al, 2016). In fact, especially estimates from lateral teeth were extremely variable and estimates from posterior teeth also varied significantly. The circumstance that we have this huge range in estimates makes it obvious that the teeth proportions of Megalodon don't correlate with that of the living Great White Shark. Subject of the studies presented in this poster is the use of the sum of the crown width of teeth from associated tooth sets as a measure for the related width of the entire jaw. Then we use this relation for a body length estimate based on the jaw proportions derived from appropriate data from modern Great White sharks and Makos. Moreover, this study is a positive example of successful collaboration between professional and amateur paleontologists, one of the priorities of the NSF funded FOSSIL project. LEDER, Ronny M., Florida Museum of Natural History, Vertebrate Paleontology Department, Dickinson Hall, 1659 Museum Rd., PO Box 117800, Gainesville, FL 32611, PEREZ, Victor J., Geological Sciences, University of Florida, Gainesville, FL 32611 and BADAUT, Teddy, Independent affiliate, Thoirette, 39530 / 39240, France, leder.ronnymaik@flmnh.ufl.edu

The megatooth shark, Otodus megalodon, is widely accepted as the largest macrophagous shark that ever lived; and yet, despite over a century of research, its size is still debated. The great white shark, Carcharodon carcharias, is regarded as the best living ecological analog to the extinct megatooth shark and has been the basis for all body length estimates to date. The most widely accepted and applied method for estimating body size of O. megalodon was based upon a linear relationship between tooth crown height and total body length in C. carcharias. However, when applying this method to an associated dentition of O. megalodon (UF-VP-311000), the estimates for this single individual ranged from 11.4 to 41.1 m. These widely variable estimates showed a distinct pattern, in which anterior teeth resulted in lower estimates than posterior teeth. Consequently, previous paleoecological analyses based on body size estimates of O. megalodon may be subject to misinterpretation. Herein, we d...

The fossil leaf horizon from the clay pit Tetta-Buchholz (Oberlausitz, Germany), discovered and rescued in summer 2006 by the paleobotany staff of the Museum der Westlausitz Kamenz,  was initially investigated for it's content on macroscopic plant remains like leafs and larger fruits and published in 2007 in number 27 of the "Veroeffentlichungen des Museums der Westlausitz". The presented leaf flora was a typical Mixed Mesophytic Forest with subtropical laurophyllic species (Daphogene) and numerous tempered summer green elements with the latter Arcto-Tertiary tribes being predominant and the laurophyllic representatives subordinate but together with the presence of Ulmus proof of the warm-tempered character of that Mixed Mesophytic Forest. Fagus and Quercus as well as Carpinus, Acer and Ulmus emerge as the dominant elements typical for the transfer from Fagetum beech forest to Querco-Ulmetum floodplain forest as the outmost part of a swamp-riparian-forest succession. The now investigated Carpoflora supports the results from 2007. Numerous elements of the Younger Mastixioideen-Flora after Mai 1976 were present. Important species are Ternstroemia sequoioides, Symplocos salzhausensis, Mastixia amygdalaeformis, Fagus decurrens and Eurya stigmosa. Important more tempered elements are Ampelopsis tertiaria, Betula longisquamosa, Carpinus miocenica, Craetegus nodulosa. Pseudolarix schmittgenii is more element of the stratigrafic older floristic assemblage Kleinleipisch (Florenzone XI after Mai 1976). The flora of Tetta-Buchholz should be placed at the beginning of the floristic assemblage Klettwitz within the transition from from floristic zone XI to XII (Florenzone XI-XII after Mai). The representatives of warm-preferring laurels and elm trees support that affiliation. The presence of Canex canescentoidea, an element of Younger Miocene floral assemblages, verifies the stratigraphic position at the transition from Upper to Middle Miocene (Florenzone XI-XII after Mai 1976, 1995).

Bei einer Tagebaubesichtigung der Tongrube Tetta-Buchholz am 3.07.2006 wurde eine bisher nicht beschriebene Fossilfundschicht innerhalb einer kohligen Tonlinse entdeckt. Es handelt sich hierbei um eine Horizontfolge fossiler Blätter und anderer Pflanzenreste. Aufgrund karpologischer Belege wurde die bisher beschriebene Paläoflora Tetta-Buchholz von Czaja & BeRneR (999) in das Mittel-miozän (Florenkomplex Klettwitz) eingestuft. Erste tertiäre Pflanzenfunde der Tongrube Tetta-Buchholz wurden bereits in der jüngeren Vergangen-heit dokumentiert und in mehreren Arbeiten publiziert (Czaja & BeRneR 999, Czaja 2000, 200, Mai 2000, 200). Auffallend ist, dass die Pflanzenvergesellschaftung aus Tetta-Buchholz neben Fruktifikationen von Vertretern der Mastixiaceen, durch den Reichtum an Koniferen, in Form von Zapfen, Zapfenschuppen, Nadeln und Samen geprägt war. Zum Teil wurden auch schlecht erhaltene fossile Blattfragmente entdeckt. Aber schon Czaja & BeRneR (1999) weisen darauf hin, dass das Vor-kommen taphonomisch autochthoner bzw. parautochthoner Blatthorizonte mit sehr gut erhaltenen vollständigen Blattfossilien höchst wahrscheinlich und zu erwarten ist. Somit war es nur eine Frage der Zeit bis entsprechende fossile Nachweise entdeckt wurden. Im Rahmen einer Vorexkursion der geologisch-paläobotanischen Abteilung des Museums der Westlau-sitz stand auch die Tongrube Tetta-Buchholz im Mittelpunkt des Interesses. Nach Hinweisen der Beleg-schaft der abbauenden Firma in Tetta-Buchholz wurde ein viel versprechender Horizont kurz über der Sohle der Tongrube untersucht. Bereits an der Oberfläche traten einige Tonplatten mit sehr gut erhal-tenen inkohlten Blättern u. a. zu Tage. Erhaltungszustand und Zugänglichkeit waren ausschlaggebend für die weitestgehend mögliche Freilegung des Horizontes und die Bergung der Fossilplatten. Hierbei wurden mehrere hundert Kilogramm fossilführender Ton abgetragen und zur weiteren Untersuchung im Magazin des Sammelsuriums des Museums der Westlausitz in Kamenz eingelagert. Die vorliegende Arbeit soll lediglich einen ersten Überblick zur Fundstelle und den bisher analysier-ten darin enthaltenen fossilen Pflanzenresten liefern. Des Weiteren werden erste Taxa vorgestellt. Die weiterführende Bearbeitung wird in nächster Zukunft am Museum der Westlausitz erfolgen und die entsprechenden Ergebnisse in der Folge publiziert.

Fossil material of the Eocene marine sediments of the Crimean Simferopol Formation (Akkaja, Prolom),
Novopavlovsk Formation and Al’Ma Formation (Bachthisarai) as well as the Kazakh Schorym
Formation (Kujulus) has been taxonomically investigated. The following 16 taxa of fossil carcharhinid
and triakid sharks could be specified: Galeorhinus ypressiensis, Iago carlaluisai n. sp., Mustelus cf. vanderhoefti,
Triakis muelleri n. sp., Triakis wardi, Triakis sp.1, Abdounia beaugei, Abdounia lappierei,
Abdounia sp., Galeocerdo latidens, Physodon contortus comb. nov., Physogaleus tertius, Physogaleus
sp., Morphospecies 1, Morphospecies 2, Morphospecies 3. Iago carlaluisai and Triakis muelleri were described
as new species. Physodon (Müller & Henle, 1839) was reintroduced as an independent genus. It
was described as sister group of Physogaleus. The proof of Physodon contortus (Winkler, 1874 B) comb.
nov. for the Middle Eocene, is the oldest fossil record of this species and one of the first safe proofs of the
species in Eurasia. The habitat of the faunal community were warm and tempered offshore waters of the
littoral (Prolom, Ak-kaja, Kujulus) up to the epipelagial (Bachthisarai). The waters were nutritious and
characterized by a high biodiversity. The presented fauna is a typical Tethys fauna and well correlated to
Middle Eocene faunas of North Africa, Europe, India, Central Asia and North America.

Die morphologische Variabilität dentaler Strukturen, bei Haien der Familie der Carcharhinidae, ist
sowohl innerhalb als auch zwischen den Arten unzureichend erforscht. Ohne Kenntnis der artspezifischen
Parameter ist eine genaue taxonomische Klassifizierung von fossilen Haien anhand der Zähne
jedoch unmöglich. Die umfassende Analyse der dentalen Strukturen rezenter carcharhinider Haie nach
artspezifischen Merkmalen wurde genutzt, um die Ergebnisse auf die nächsten fossilen Verwandten zu
übertragen. Besonderes Augenmerk galt darüber hinaus dem morphologischen Vergleich fossiler Zähne
westatlantischer und zentralasiatischer Herkunft. Es wurde ein morphometrisches Analyseverfahren
entwickelt, dass entgegen bestehender Methoden, gänzlich auf manuelle Datengewinnung verzichtet. Für
die neue Methode der automatisierten algorithmischen Morphometrie (AAM) wurden erstmals, anhand
von 2340 Einzelzähnen von 112 Individuen aus 41 Arten rezenter Carcharhinidae, die wesentlichen artspezifischen
Merkmalskomplexe definiert und in ein Analyseprogramm samt Datenbank übertragen. Die
Einzeluntersuchung der einzelnen Spezies nach Gesichtspunkten ontogenetischer, sexueller bzw. mono-/
dignather Heterodontie sowie intra- und interspezifischer Varianz der Zahnmorphologie zeigte, dass carcharhinide
Haie allein mit Hilfe zahnmorphologischer Merkmale identifiziert werden können und diese
Merkmale für systematische Zwecke geeignet sind. Der Erfolg der systematischen Zuordnung steht aber
in direkter Abhängigkeit zur Zahnposition und zur betrachteten Spezies. Der Einfluss der Heterodontie
auf die taxonomische Aussagekraft ist mitunter enorm, so dass die Eindeutigkeit der taxonomischen
Klassifizierung stark begrenzt wird. Es existiert eine enorme Bandbreite an morphologischen Überschneidungen
und Durchdringungen, sowohl innerhalb der Arten als auch art- bzw. gattungsübergreifend.
Beim Vergleich allein anhand einzelner Zähne, sowohl fossiler als auch rezenter Herkunft, ist es in vielen
Fällen nicht feststellbar, ob noch innerartliche Varianz oder bereits artliche Differenz vorliegt. Aus den
Erkenntnissen der morphometrischen Analyse und deren Übertragung auf die fossilen Belege, ergab sich
die Notwendigkeit, fossile Zähne carcharhinider Haie zukünftig, neben dem bestehenden deskriptiven
Verfahren der Taxonomie, zusätzlich funktionsmorphologisch zu beurteilen. Dazu wurden erstmals sechs
funktionsmorphologische Gruppen definiert, mit deren Hilfe vor allem ökologische Schlussfolgerungen
bei der Bewertung fossiler Zähne möglich sind.

The morphological variability of dental structures of carcharhinid sharks within and between the different specimens is unsufficiently investigated. Without knowledge of the species specific parameter exact taxonomic classification of fossil sharks based on their teeth is nearly impossible. A comprehensive
analysis of dental structures of recent carcharhinid sharks for species specific attributes was used to transfer the results to their next fossil relatives. Special attention was directed to morphological comparison between fossil teeth from West Atlantic and Central Asian origin. Against existing methods a
morphometric analysis model was developed that avoids manual data collection by reducing the shape data with a matrix of different transcription methods like distance transformation. The new method of automatic algorithmic morphometry (AAM) defined the crucial species specific attribute complexes by analysing more than 3000 single teeth from 120 individuals of 41 species of recent carcharhinids and tranfered the data into a new developed analysis program along with a special database. The individual study of every single specimen in terms of ontognetic, sexual respectively mono- / dignath heterodonty as well as
intra- and interspecific variance in tooth morphology proofed the fact that identifying carcharhinid sharks just by means of tooth morphological attributes is possible and that these attributes are qualified for systematic purposes. The success of the systematic classification is highly depending on the tooth position and the investigated species. The heterodonty influence on the taxonomic significance is occasionally tremendous wich strongly reduces the
unambiguity of the classification. An enormous bandwidth in morphological overlap and interpenetration within the severall species as well as across species and genus leve is existing. Within the comprehensive study using just single teeth of fossil or recent origin it is sometimes impossible to clarify if there is just a innerspecific variance or already a species specific difference. From the results of the morphometric analysis and the tranfer of the data to the fossil record resulted the necessity to evaluate fossil teeth of carcharhinid sharks not just with the existing descriptive methods of taxonomy but also to use more
aspects of functional morphology. Therefore six functional morphologic groups where defined for the first time whereby ecological conclusions are possible.

The great natural history collections in museums, universities and other academic intitutions all over the world are the backbone of national and international research in taxonomy, biodiversity and evolution. But getting access to those resources is mostly limited to academics. The main goal of the Integrated Digitized Biocollections project, in short iDigBio, is to collect data and images for millions of biological specimens and make them available in electronic format for the research community, government agencies, students, educators, and the general public. It is the National Resource for Advancing Digitization of Biodiversity Collections (ADBC) funded by the National Science Foundation (NSF). The bulk of the collections, especially for fossils, has its origin in private engagement and was donated by private collectors and enthusiasts. Even the most iconic of fossils (e.g. Archaeopteryx lithographica, von Meyer 1861) stem from the playground of amateur paleontologists and private collectors. It is hard to imagine how much more may lie dormant unnoticed in private cabinets. The NSF funded FOSSIL project is focused on getting access to these treasures in building connections in the paleontological community. It is the core of a big network between amateurs and professionals. How can iDigBio and FOSSIL get along? While iDigBio is the big online collection for the bio-community, FOSSIL is part of this community. It helps the paleo-people getting together, communicate in a simple form and tear down boarders between the academics and the public. It is focused on attracting fossil hunters of all ages and level of experience to participate in academic research in general and to provide professional digital databases like myFOSSIL and iDigBio with input that was recently mostly unreachable. To that end, the Fossil Project in partnership with iDigBio has begun training amateurs to fulfill all the requirements needed to not just get access into the databases but also to be part of the FOSSIL and iDigBio world in donating their treasures in digital form. As amateurs gain skills, we anticipate increased interest and participation in the international effort to digitize collections.

In the filling of a sinkhole within the Lower Muschelkalk at the limestone quarry of the cement plant Karsdorf, beside fossil rich Upper Muschelkalk, also Palaeogene fossil material was found. The Muschelkalk part of the fi lling consists of approximately 50 m of Upper Muschelkalk and contains fossil material from the tetractinella bed (Trochitenkalk facies) up to the cycloides bed. The Palaeogene sediments of the collapse mass are not decalcifi ed and include a carpofl ora, rests of molluscs and vertebrates. The carpological samples show a wide stratigraphic range. Some species seem to be of Lower Eocene age or older (Tinospora wikinsonii Chandler) and correspond with appropriate fl oras from England like the London Clay; others are present from Eocene to Miocene. Most of the samples belong to Nyssaceans, Vitaceans, Menispermaceans and submerse swamp and aquatic plants (Potamogeton, Stratiotes, Sparganium, Ceratophyllum). Most of the small and fragile bone fragments belong to amphibians but also a lot of reptile material like turtles (Testudinoidea) and crocodiles were found. Special attention refers to mammal and bird remains. Exemplary the oldest rodent record in Germany (Paramyidae) needs to be mentioned. The faunistic fossils indicate close relations to the stratigraphically and spatially similar Geiseltal. In particular the gastropods Australorbis, Galba and Carychiopsis indicate close relations with the gastropod faunas of Geiseltal. Therefore most of the faunistic fossil content suggests a stratigraphic classifi cation in the Middle Eocene, but especially the carpofl ora indicates the possibility that the subrosion has already started in the Lower Eocene or earlier. With our data it is possible to more exactly determine the period of leaching in the Rötsalinar and thus the development of the sinkhole.

From Atzendorf (Sachsen-Anhalt, Salzlandkreis,
Egelner Nordmulde) the first consistently
palaeontological investigated profile of the Silberberg
Formation (Paleogene, Priabonian/Rupelian) will be
discussed here. During last years (from 2008 to 2010)
the profile was opened by excavating seven mining
dugs. The complete section has been sampled in detail
(15 cm intervals), and completely evaluated. The
main results of the first step of investigation include
following essential points:
1. The Silberberg Formation comprises rich and well
preserved benthic fossil communities characterized
by high diversities versus low densities. Furthermore,
highly diverse fish associations were observed.
2. Mass occurences of pteropods allow a very detailed
biostratigraphical subdivision of the Silberberg
Formation as well as long distance correlations with
other localities in the southern North Sea Basin.
3. The Silberberg Formation (NP21) comprises two
parasequences. This correlates with observations made
by Krutzsch (2008) in the Upper Schönewald Formation
(Northeast Germany), and by Blumenstengel et al.
(1996) in the Zöschen Formation (Halle-Merseburg).
4. Based on the new observations an informal model
of lithostratigraphy of the Silberberg Formation has
been established. For the lower parasequence the term
Marbe Subformation has been introduced, and for the
upper parasequence the term Atzendorf-Subformation.
5. The second parasequence (Atzendorf
Subformation) indicates the maximum sea level and
the maximum expansion of the „Latdorfian“ sea. At
this time the „Magdeburg Corridor“ (Krutzsch 2008)
has been flooded. Using pteropods (Creseis cincta
v. Koenen 1894) as biostratigraphical markers the
Atzendorf Subformation correlates with the sands
of Grimmertingen (Belgium, Sint Huibrechts/Hern
Formation). The Marbe Subformation may correlate
with the Bassevelde 2 sands (Zelzate Formation) in
Belgium (see Van Simaeys, de Man & Vandenberghe
2007).

Zusammenfassung: Beschrieben wird eine Kollektion paläogener Pflanzenreste. Mitte der 1990er Jahre vom Privatsammler H. Huhle zusammengetragen, stellt die fossile Flora von Querfurt den einzig erhaltenen paläobotanischen Nachweis aus tertiären Sedimenten der Querfurter Mulde dar. Diese Flora wurde taxonomisch beschrieben und dokumentiert, auch um das Bild der gegenwärtig bekannten känozoischen Paläofloren Mitteldeutschlands um einen weiteren Fundpunkt an der westlichen Erosionsgrenze zu erweitern und die Arbeiten von RÜFFLE, MÜLLER-STOLL & LITTKE, MAI & WALTHER etc. zu ergänzen. Anhand der Untersuchungen bezüglich der Taxonomie konnten die Pflanzenreste biostratigrafisch dem höheren Mitteleozän zugeordnet werden. Diese Flora entspricht der " Älteren Mastixioideenflora " im Sinne von MAI (1964), die Klimaxgesellschaft zeigte Lorbeerwaldcharakter. Im Weiteren ist die vorliegende Arbeit ein erster Teil, um den aktuellen Stand der Aufschlusssituation fossilreicher tertiärer Sedimente abseits der klassischen Braunkohlegruben zu dokumentieren.

Fossil remains of selachiens and chimaera from the Muschelschluff and Phosphoritknollenhorizont (Böhlen-Formation) of Zwenkau near
Leipzig were described. The findings comprise new taxa or taxa that for the appropriate strata very rare are. Beside the new described genus
Arnomobula gen. nov., the mobuloid rays Arnomobula eythrai gen. et spec. nov. and Argoubia arnoldmülleri spec. nov. as well as the scyliorhinid
shark Scyliorhinus kannenbergi spec. nov. were described and verified as new species. As type horizons the Phosphoritknollenhorizont
and Muschelschluff were determined. Beside the first description of oral teeth of the saw shark Pristiophorus rupeliensis Steuerbaut & Herman
1987 for the fossil site further pretty rare rostral teeth of the species as well as a fragment of the palatinal tooth plate of Chimaera gosseleti Winkler
1880 could be described. The fossil samples mirror the faunal progress in a marginal sea at the maximum transgression of the North Sea.

Since the first time a Megalodon shark tooth was found and identified as such, the question of the actual size of one of the Neogene top predators was the subject of imaginative speculation and scientific investigation. Both the results and the methods that are used to determine the size led to enormous dimensions in each case but are still quite diverse and bear a high potential for uncertainty. The problem with the recently most used estimation methods like those from Gottfried (1996) and Shimada (2002) is that they make body length estimates based on isolated teeth rather than entire dentitions. After testing the validity of the body length estimates from Shimada, which is the most accepted at the moment, by using several associated dentitions from C. megalodon, we noticed an extreme variability of the body length estimates depending on the tooth position in the jaw (Perez et al, 2016). In fact, especially estimates from lateral teeth were extremely variable and estimates from posterior teeth also varied significantly. The circumstance that we have this huge range in estimates makes it obvious that the teeth proportions of Megalodon don't correlate with that of the living Great White Shark. Subject of the studies presented in this poster is the use of the sum of the crown width of teeth from associated tooth sets as a measure for the related width of the entire jaw. Then we use this relation for a body length estimate based on the jaw proportions derived from appropriate data from modern Great White sharks and Makos. Moreover, this study is a positive example of successful collaboration between professional and amateur paleontologists, one of the priorities of the NSF funded FOSSIL project.

LEDER, Ronny M., Florida Museum of Natural History, Vertebrate Paleontology Department, Dickinson Hall, 1659 Museum Rd., PO Box 117800, Gainesville, FL 32611, PEREZ, Victor J., Geological Sciences, University of Florida, Gainesville, FL 32611 and BADAUT, Teddy, Independent affiliate, Thoirette, 39530 / 39240, France, leder.ronnymaik@flmnh.ufl.edu