Sauropod trackways of the Iberian Peninsula: palaeoetological and palaeoenvironmental implications

Abstract

More than a hundred sauropod tracksites, ranging in age from Middle Jurassic (Bathonian) to Late Cretaceous (Maastrichtian), are reported from the Iberian Peninsula (Spain and Portugal). Sauropod trackway orientation patterns throughout an entire geographic area such as the Iberian Peninsula and over different time periods may provide new data about the palaeoecology and behavioural patterns of sauropods. The studied tracksites exhibit two main trackway orientation patterns, directional and random, indicating different behaviours in gregarious or solitary (milling) individuals. Gregarious behavioural patterns are mainly observed within Parabrontopodus/Breviparopus-like and Brontopodus-like ichnotypes of a single size class (either small or medium-sized), indicating age segregation. Among the gregarious sauropods the former ichnotype is linked with inland environments, while the latter is mainly linked with coastal environments. Solitary trackways are mainly of medium-sized to large individuals, are also linked with both inland (Parabrontopodus/Breviparopus-like) and coastal environments (Parabrontopodus/Breviparopus-like, Brontopodus-like), and belong to the above-mentioned ichnotypes as well as to Polyonyx-like ichnotypes. Thus, no obvious link between gregarious behaviour and the palaeoenvironmental setting can be inferred from the sauropod track record of the Iberian Peninsula. Nonetheless, sauropod trackways showing titanosauriform characters (Brontopoduslike) are more common in coastal environments, contrary to what might be expected given this group's apparent taxonomic preference for inland environments.Keywords: Sauropod trackways, palaeoecology, gregarious behaviour, Jurassic, Cretaceous, Iberian Peninsula Resumen El registro Ibérico (España y Portugal) de icnitas de saurópodos está representado por más de cien yacimientos cuya edad varía desde el Jurásico Medio (Batoniense) al Cretácico Superior (Maastrichtiense). El estudio de la orientación de los rastros, en un área determinada como la Península Ibérica y en diferentes edades, nos ha permitido obtener nuevos datos sobre el comportamiento de los saurópodos. Los rastros de los yacimientos estudiados presentan dos patrones de movimiento distintos, direccionales y aleatorios, que reflejan distintos comportamientos en individuos gregarios o solitarios (deambulantes). El patrón que indica comportamiento gregario se observa en los icnotipos "Parabrontopodus/Breviparopus-like" y "Brontopodus-like" en saurópodos del mismo tamaño (pequeño o medio), lo que indica segregación por edad. El primer icnotipo se ha conservado en sedimentos depositados en ambientes terrestres mientras que el segundo lo hace fundamentalmente en ambientes costeros. Los rastros solitarios son, en su mayoría, de saurópodos de tamaño medio o grande, conservados tanto en medios terrestres ("Parabrontopodus/Breviparopus-like"), como costeros ("Parabrontopodus/Breviparopus-like" y "Brontopodus-like") y pertenecen a los dos icnotipos mencionados anteriormente y a un tercero: "Polyonyx...

Late Jurassic–Early Cretaceous trackways of small-sized sauropods from China: New discoveries, ichnotaxonomy and sauropod manus morphology

“…Ishigaki and Matsumoto, 2009;Castanera et al, 2012Castanera et al, , 2014, showing an increase of the footprint rotation angle during turn. Two trackways consist mostly of pes traces.…”

“…The former have been correlated with diplodocoid sauropods, the latter with titanosauriform sauropods, proving that gait and heteropody patterns help distinguish different sauropod groups (Farlow, 1992;Lockley et al, 1994b. Wilson andCarrano, 1999;Wright, 2005;Henderson, 2006;Romano et al, 2007;Santos et al, 2009;Castanera et al, 2012Castanera et al, , 2014Vila et al, 2013). Ultimately a comprehensive global synthesis of all useful (morphologically diagnostic) sauropod trackway data is just as desirable as an equivalent synthesis of skeletal data.…”

Descripción de las huellas de camélidos y félidos de la localidad Pie de Vaca, Cenozoico Tardío de Puebla, centro de México y algunas consideraciones paleobiológicas

“…Por lo anterior, es probable que los camélidos que generaron los rastros hayan sido representantes de ese género de lamines, el cual fue bastante común a lo largo del territorio nacional durante el Cenozoico tardío (Jiménez-Hidalgo y Carranza-Castañeda, 2010; Bravo-Cuevas et al, 2012, 2016a. La dirección de los rastros, los valores de velocidad y modalidad de progresión de los organismos que los produjeron, así como la profundidad de las huellas, son evidencia utilizada para establecer un comportamiento gregario a través de huellas (Castanera et al, 2012). La distribución y dirección de los rastros de camélidos de Pie de Vaca se asociaría a un grupo de cinco individuos que se dirigen hacia el sureste (RC 1, 2, 5, 8 y 9) y otro grupo de cuatro individuos que se desplazan hacia el norte-noreste (RC 3, 4, 6 y 7).…”

Preface. Palaeodiversity and Palaeoecology of Iberian Ecosystems. New insights into the Phanaerozoic biotas from Spain and Portugal

“…The fossil record of dinosaurs -both bones and tracks-is well represented in the Jurassic and Cretaceous sediments of the Iberian Peninsula. Accordingly, the interval from the Middle Jurassic to the Late Cretaceous fossil record from Portugal and Spain has delivered numerous trackways of sauropods, Dinosauria's largest representatives, evidencing gregarious and solitary movements linked to different environments (Castanera et al, 2014). However, the gregarious behavior was not limited to sauropod dinosaurs.…”

“…At a lesser scale, the Lower Cretaceous tracksites from the Cameros Basin in La Rioja reveal that other dinosaur groups like theropods and ornithopods share this condition, at least for some seasons or some periods of their lives (García-Ortiz and Pérez-Lorente, 2014). Unlike Castanera et al (2014), the data obtained from the Cameros Basin to infer patterns of gregarious behaviors in dinosaurs is not only provided by trackways, but also by dinoturbated layers.…”