scholarly journals A walk in the maze: variation in Late Jurassic tridactyl dinosaur tracks from the Swiss Jura Mountains (NW Switzerland)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4579 ◽  
Author(s):  
Diego Castanera ◽  
Matteo Belvedere ◽  
Daniel Marty ◽  
Géraldine Paratte ◽  
Marielle Lapaire-Cattin ◽  
...  
Keyword(s):  
Late Jurassic ◽  
3D Models ◽  
Width Ratio ◽  
Shape Variation ◽  
Jura Mountains ◽  
Depth Maps ◽  
False Color ◽  
Dinosaur Tracks ◽  
Nw Switzerland ◽  
Color Depth

BackgroundMinute to medium-sized (footprint length (FL) less than 30 cm) tridactyl dinosaur tracks are the most abundant in the Late Jurassic tracksites of Highway A16 (Reuchenette Formation, Kimmeridgian) in the Jura Mountains (NW Switzerland). During excavations, two morphotypes, one gracile and one robust, were identified in the field. Furthermore, two large-sized theropod ichnospecies (Megalosauripus transjuranicusandJurabrontes curtedulensis) and an ornithopod-like morphotype (Morphotype II) have recently been described at these sites.MethodsThe quality of morphological preservation (preservation grade), the depth of the footprint, the shape variation, and the footprint proportions (FL/footprint width (FW) ratio and mesaxony) along the trackways have been analyzed using 3D models and false-color depth maps in order to determine the exact number of small to medium-sized morphotypes present in the tracksites.ResultsThe study of footprints (n= 93) recovered during the excavations has made it possible to identify and characterize the two morphotypes distinguished in the field. The gracile morphotype is mainly characterized by a high FL/FW ratio, high mesaxony, low divarication angles and clear, sharp claw marks, and phalangeal pads (2-3-4). By contrast, the robust morphotype is characterized by a lower FL/FW ratio, weaker mesaxony, slightly higher divarication angles and clear, sharp claw marks (when preserved), whereas the phalangeal pads are not clearly preserved although they might be present.DiscussionThe analysis does not allow the two morphotypes to be associated within the same morphological continuum. Thus, they cannot be extramorphological variations of similar tracks produced by a single trackmaker. Comparison of the two morphotypes with the larger morphotypes described in the formation (M. transjuranicus,J. curtedulensis, and Morphotype II) and the spatio-temporal relationships of the trackways suggest that the smaller morphotypes cannot reliably be considered as small individuals of any of the larger morphotypes. The morphometric data of some specimens of the robust morphotype (even lower values for the length/width ratio and mesaxony) suggest that more than one ichnotaxon might be represented within the robust morphotype. The features of the gracile morphotype (cf.Kalohipusisp.) are typical of “grallatorid” ichnotaxa with low mesaxony whereas those of the robust morphotype (cf.Therangospodusisp. andTherangospodus? isp.) are reminiscent ofTherangospodus pandemicus. This work sheds new light on combining an analysis of variations in footprint morphology through 3D models and false-color depth maps, with the study of possible ontogenetic variations and the identification of small-sized tridactyl ichnotaxa for the description of new dinosaur tracks.

scholarly journals A walk in the maze: Variation in Late Jurassic tridactyl dinosaur tracks - A case study from the Late Jurassic of the Swiss Jura Mountains (NW Switzerland)

2018 ◽  
Author(s):  
Diego Castanera ◽  
Matteo Belvedere ◽  
Daniel Marty ◽  
Géraldine Paratte ◽  
Marielle Lapaire-Cattin ◽  
...  
Keyword(s):  
Late Jurassic ◽  
3D Models ◽  
Width Ratio ◽  
Shape Variation ◽  
Jura Mountains ◽  
Depth Maps ◽  
Dinosaur Tracks ◽  
Length Width ◽  
Nw Switzerland ◽  
False Colour

Background. Minute to medium-sized (FL less than 30 cm) tridactyl dinosaur tracks are the most abundant in the Late Jurassic tracksites of Highway A16 (Reuchenette Formation, Kimmeridgian) in the Jura Mountains (NW Switzerland). During excavations, two morphotypes, one gracile and one robust, were identified in the field. Furthermore, two large-sized theropod ichnospecies (Megalosauripus transjuranicus and Jurabrontes curtedulensis) and an ornithopod-like morphotype (Morphotype II) have recently been described at these sites. Methods. The quality of preservation (preservation grade), the depth of the footprint, the shape variation and the footprint proportions (FL/FW ratio and mesaxony) along the trackways have been analysed using 3D models and false-colour depth maps in order to determine the exact number of morphotypes present in the tracksites. Results. The study of the footprints (n = 93) collected during the excavations has made it possible to identify and characterize the two morphotypes distinguished in the field. The gracile morphotype is mainly characterized by a high footprint length/width ratio, high mesaxony, low divarication angles and clear, sharp claw marks and phalangeal pads (2-3-4). By contrast, the robust morphotype is characterized by a lower footprint length/width ratio, weaker mesaxony, slightly higher divarication angles and clear, sharp claw marks (when preserved), whereas the phalangeal pads are not clearly preserved although they might be present. Discussion. The analysis does not allow the two morphotypes to be associated within a morphological continuum. Thus, they cannot be a consequence of extramorphological variations on similar tracks produced by a similar/single trackmaker. Comparison of the two morphotypes with the larger morphotypes described in the formation (Megalosauripus transjuranicus, Jurabrontes curtedulensis and Morphotype II) and the spatio-temporal relationships of the trackways suggest that the smaller morphotypes cannot reliably be considered small individuals of the larger morphotypes. The morphometric data of some specimens of the robust morphotype (even lower values for the length/width ratio and mesaxony) suggest that more than one ichnotaxon might be represented within the robust morphotype. The features of the gracile morphotype (cf. Kalohipus) are typical of “grallatorid” ichnotaxa with low mesaxony whereas those of the robust morphotype (cf. Therangospodus and ?Therangospodus) are reminiscent of Therangospodus pandemicus. This work sheds new light on combining an analysis of variations in footprint morphology through 3D models and false-colour depth maps, with the study of possible ontogenetic variations and the identification of small-sized tridactyl ichnotaxa for the description of new dinosaur tracks.

scholarly journals A walk in the maze: Variation in Late Jurassic tridactyl dinosaur tracks - A case study from the Late Jurassic of the Swiss Jura Mountains (NW Switzerland)

2018 ◽  
Author(s):  
Diego Castanera ◽  
Matteo Belvedere ◽  
Daniel Marty ◽  
Géraldine Paratte ◽  
Marielle Lapaire-Cattin ◽  
...  
Keyword(s):  
Late Jurassic ◽  
3D Models ◽  
Width Ratio ◽  
Shape Variation ◽  
Jura Mountains ◽  
Depth Maps ◽  
Dinosaur Tracks ◽  
Length Width ◽  
Nw Switzerland ◽  
False Colour

Background. Minute to medium-sized (FL less than 30 cm) tridactyl dinosaur tracks are the most abundant in the Late Jurassic tracksites of Highway A16 (Reuchenette Formation, Kimmeridgian) in the Jura Mountains (NW Switzerland). During excavations, two morphotypes, one gracile and one robust, were identified in the field. Furthermore, two large-sized theropod ichnospecies (Megalosauripus transjuranicus and Jurabrontes curtedulensis) and an ornithopod-like morphotype (Morphotype II) have recently been described at these sites. Methods. The quality of preservation (preservation grade), the depth of the footprint, the shape variation and the footprint proportions (FL/FW ratio and mesaxony) along the trackways have been analysed using 3D models and false-colour depth maps in order to determine the exact number of morphotypes present in the tracksites. Results. The study of the footprints (n = 93) collected during the excavations has made it possible to identify and characterize the two morphotypes distinguished in the field. The gracile morphotype is mainly characterized by a high footprint length/width ratio, high mesaxony, low divarication angles and clear, sharp claw marks and phalangeal pads (2-3-4). By contrast, the robust morphotype is characterized by a lower footprint length/width ratio, weaker mesaxony, slightly higher divarication angles and clear, sharp claw marks (when preserved), whereas the phalangeal pads are not clearly preserved although they might be present. Discussion. The analysis does not allow the two morphotypes to be associated within a morphological continuum. Thus, they cannot be a consequence of extramorphological variations on similar tracks produced by a similar/single trackmaker. Comparison of the two morphotypes with the larger morphotypes described in the formation (Megalosauripus transjuranicus, Jurabrontes curtedulensis and Morphotype II) and the spatio-temporal relationships of the trackways suggest that the smaller morphotypes cannot reliably be considered small individuals of the larger morphotypes. The morphometric data of some specimens of the robust morphotype (even lower values for the length/width ratio and mesaxony) suggest that more than one ichnotaxon might be represented within the robust morphotype. The features of the gracile morphotype (cf. Kalohipus) are typical of “grallatorid” ichnotaxa with low mesaxony whereas those of the robust morphotype (cf. Therangospodus and ?Therangospodus) are reminiscent of Therangospodus pandemicus. This work sheds new light on combining an analysis of variations in footprint morphology through 3D models and false-colour depth maps, with the study of possible ontogenetic variations and the identification of small-sized tridactyl ichnotaxa for the description of new dinosaur tracks.

scholarly journals Thalassemys bruntrutanan. sp., a new coastal marine turtle from the Late Jurassic of Porrentruy (Switzerland), and the paleobiogeography of the Thalassemydidae

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1282 ◽  
Author(s):  
Christian Püntener ◽  
Jérémy Anquetin ◽  
Jean-Paul Billon-Bruyat
Keyword(s):  
Late Jurassic ◽  
Marine Turtle ◽  
Jura Mountains ◽  
Marine Turtles ◽  
The Past ◽  
Coastal Marine ◽  
New Material ◽  
Swiss Jura ◽  
Nw Switzerland ◽  
A New Species

Background.The Swiss Jura Mountains are a key region for Late Jurassic eucryptodiran turtles. Already in the mid 19th century, the Solothurn Turtle Limestone (Solothurn, NW Switzerland) yielded a great amount of Kimmeridgian turtles that are traditionally referred to Plesiochelyidae, Thalassemydidae, and Eurysternidae. In the past few years, fossils of these coastal marine turtles were also abundantly discovered in the Kimmeridgian of the Porrentruy region (NW Switzerland). These findings include numerous sub-complete shells, out of which we present two new specimens ofThalassemys(Thalassemydidae) in this study.Methods.We compare the new material from Porrentruy to the type speciesTh. hugii, which is based on a well preserved specimen from the Solothurn Turtle Limestone (Solothurn, Switzerland). In order to improve our understanding of the paleogeographic distribution ofThalassemys, anatomical comparisons are extended toThalassemysremains from other European countries, notably Germany and England.Results.While one of the twoThalassemysspecimens from Porrentruy can be attributed toTh. hugii, the other specimen represents a new species,Th. bruntrutanan. sp. It differs fromTh. hugiiby several features: more elongated nuchal that strongly thickens anterolaterally; wider vertebral scales; proportionally longer plastron; broader and less inclined xiphiplastron; wider angle between scapular process and acromion process. Our results show thatTh. hugiiandTh. bruntrutanaalso occur simultaneously in the Kimmeridgian of Solothurn as well as in the Kimmeridgian of England (Kimmeridge Clay). This study is an important step towards a better understanding of the paleobiogeographic distribution of Late Jurassic turtles in Europe.

scholarly journals On the evaluation of chicken egg shape variability

2008 ◽  
Vol 56 (5) ◽  
pp. 69-74 ◽  
Author(s):  
Miroslav Havlíček ◽  
Šárka Nedomová ◽  
Jana Simeonovová ◽  
Libor Severa ◽  
Ivo Křivánek
Keyword(s):  
Shape Index ◽  
Width Ratio ◽  
Geometrical Parameters ◽  
Fourier Descriptors ◽  
Shape Variation ◽  
Egg Volume ◽  
Maximum Width ◽  
Chicken Egg ◽  
Egg Shape ◽  
Elliptic Fourier Descriptors

Although recently reported models for determining egg shape are highly accurate, certain com­pli­ca­ted measurements or computations are to be performed. Thus relatively simple and attainable analysis methods of chicken egg shape variability were chosen and used for the purpose of presented research. Sample of 250 eggs of ISA BROWN strain was examined. Geometrical parameters were measured and calculated with following expression of their coefficient of variation – namely egg length 3.56 %, egg maximum width 2.84 %, shape index 3.80 %, surface area 5.08 %, and egg volume 7.23 %. The second method consisted in shape quantitative measuring by the score of the principal components of elliptic Fourier descriptors (EFDs). The first four principles components which could explain over 99 % of the egg shape variations were found to be very good measures of the monitored phenomenon. It was found that 87.41 % of the total shape variation can be accounted to length to width ratio. Usefulness and relevance of the shape index usage was confirmed.

Leaf Architecture of Hoya incrassata Warb. and Hoya crassicaulis Elmer x Kloppenb. (Apocynaceae): Taxonomic Identification and Conservation Concerns

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Angela Marie M. Villareal ◽  
Inocencio E. Buot Jr.
Keyword(s):  
The Philippines ◽  
Conservation Strategies ◽  
Width Ratio ◽  
Secondary Vein ◽  
Shape Variation ◽  
Leaf Architecture ◽  
Forest Protection ◽  
Primary Vein ◽  
Acuminate Apex ◽  
Entire Margin

Hoya incrassata Warb. and Hoya crassicaulis Elmer x Kloppenb, both Philippine endemics have been always thought to be one species. Leaf architecture study of the two controversial species were examined to determine if they have similar characteristics in terms of leaf architecture, the main morphological character used in fossil studies and in taxonomic works dealing with sterile plant specimens. The unifying characters of the two species are the symmetrical and unlobed blade, acuminate apex, entire margin, pinnate primary vein, straight primary vein course, weak brochidodromous secondary vein, moderate relative secondary vein thickness, sinuous secondary vein course, loop-forming branches, enclosed by 3° or 4° arches, composite intersecondary veins, random reticulate tertiary vein, regular polygonal reticulate quaternary vein, looped ultimate marginal venation, and random areole arrangement. The characters blade length to width ratio, blade class and form, base shape, variation in secondary vein angle of divergence, and areole development delineates the two species apart. The study proved that H. incrassata and H. crassicaulis are two different species. Leaf architecture can be of great use when identifying and classifying seemingly similar plant species and sterile specimens. As both species are endemics to the Philippines, conservation ought to be massive as these species can be lost anytime with forest destruction. Conservation strategies could include forest protection and domestication.     Keywords - Botany, leaf architecture, taxonomy, Hoya crassicaulis, Hoya incrassata, Philippines

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