Papers by Fancisco J. Vega
Geologija, 2020
The cuticle structure of fossil decapod crustaceans is an important tool, not only for palaeocolo... more The cuticle structure of fossil decapod crustaceans is an important tool, not only for palaeocological and taphonomic interpretations, but also as a potential way to characterise systematically genera and even species the cuticle of which has not been severely altered by diagenetic processes. Localities with abundant decapod crustacean remains can be interpreted either as reflecting mass mortality events or just simple accumulations of exuviae, on the basis of completeness and comparison of cuticle structures between specimens of the same species from different localities. Association with anoxic events by microfacies analyses can offer clues to explain the unusual abundance of decapod crustacean remains. This is the case for the Early Cretaceous lobster Atherfieldastacus magnus (M'Coy, 1849), which is found in large numbers in different Lower Cretaceous (mainly Aptian) lithostratigraphic units across the globe. In this case, we document the well-preserved cuticle structure of specimens from the upper Aptian of Chihuahua (Mexico), preserved three-dimensionally, mainly in concretions, which were studied in different transverse sections showing the cuticle in diverse portions of the lobster body. Thin cuticle layers show the typical crustacean cuticular structure that suggest these are corpses preserved in an anoxic environment.
Journal of South American Earth Sciences, 2019
Several specimens of the mecochirid lobster Atherfieldastacus magnus (MʼCoy, 1849) collected in M... more Several specimens of the mecochirid lobster Atherfieldastacus magnus (MʼCoy, 1849) collected in Mexico and Colombia, represent the oldest record for this species. The
Journal of South American Earth Sciences, 2019
Several specimens of the mecochirid lobster Atherfieldastacus magnus (MʼCoy, 1849) collected in M... more Several specimens of the mecochirid lobster Atherfieldastacus magnus (MʼCoy, 1849) collected in Mexico and Colombia, represent the oldest record for this species. The Mexican specimens are from the Valanginian-Hauterivian San Juan Raya Formation, in Puebla, central Mexico, and the Colombian specimens were found in Barremian deposits of the Paja Formation, north of Bogotá. Previous reports of Atherfieldastacus magnus include numerous specimens from the Aptian of Europe (UK, Spain), Mexico, Colombia and Tibet. The new specimens collected in shales of the San Juan Raya Formation of Mexico, represent diverse sizes and excellent quality of preservation; in some samples the articles of the antennae can be observed, among other morphological characters not reported previously for this species. The association of the Mexican specimens with mollusks, echinoids and cones of an araucaria gymnosperm, suggest a shallow marine environment. The same is observed for the Colombian specimens, where sediments of the Paja Formation are reported as shallow marine. Additionally, sexual dimorphism in A. magnus is recognized, based on the analysis of differential morphology of the pleurae. Thus, for the moment, the biostratigraphic range for A. magnus ranges from the Valanginian to the Albian (Early Cretaceous), with the oldest occurrence in Mexico, where it persisted until Aptian times.
Geologija, 2020
The cuticle structure of fossil decapod crustaceans is an important tool, not only for palaeocolo... more The cuticle structure of fossil decapod crustaceans is an important tool, not only for palaeocological and taphonomic interpretations, but also as a potential way to characterise systematically genera and even species the cuticle of which has not been severely altered by diagenetic processes. Localities with abundant decapod crustacean remains can be interpreted either as reflecting mass mortality events or just simple accumulations of exuviae, on the basis of completeness and comparison of cuticle structures between specimens of the same species from different localities. Association with anoxic events by microfacies analyses can offer clues to explain the unusual abundance of decapod crustacean remains. This is the case for the Early Cretaceous lobster Atherfieldastacus magnus (M'Coy, 1849), which is found in large numbers in different Lower Cretaceous (mainly Aptian) lithostratigraphic units across the globe. In this case, we document the well-preserved cuticle structure of specimens from the upper Aptian of Chihuahua (Mexico), preserved three-dimensionally, mainly in concretions, which were studied in different transverse sections showing the cuticle in diverse portions of the lobster body. Thin cuticle layers show the typical crustacean cuticular structure that suggest these are corpses preserved in an anoxic environment.
Journal of South American Earth Sciences, 2019
León and Moreno-Bedmar, new species, are reported. This assemblage bears similarities with crusta... more León and Moreno-Bedmar, new species, are reported. This assemblage bears similarities with crustaceans reported from the upper Albian of the Pawpaw Shale of Texas and to other reef crustaceans from the Late Jurassic and Early Cretaceous of Europe. This is first record in the Americas for some genera. The here reported specimens are found associated to sponges, corals, mollusks and bryozoans, that suggest a shallow marine reef environment for this region of Central Mexico during late Barremian times. All of the specimens represent isolated dorsal carapaces, some with evidence of little transport.
Cretaceous Research, 2017
Three specimens of the lobster "Meyeria rapax", which represent the first record of this species ... more Three specimens of the lobster "Meyeria rapax", which represent the first record of this species in Spain, were collected in the Artoles Formation cropping out in the surroundings of the town of Ares del Maestrat in the Maestrat Basin. Microfacies and paleontological analyses of the sedimentary succession containing the fossil lobsters allow us to infer a near-coastal depositional setting. Numerical ages derived from Sr-isotope analyses combined with previous chronostratigraphic studies of the Artoles Formation suggest an early Barremian age for the stratigraphic interval, which is located around the middle part of the formation, with lobsters studied. The study of the morphological features observed in the record of the "Meyeria rapax" specimens from Spain supports the ascription of the species to the new genus Atherfieldastacus proposed recently for the Mecochiridae family.
CIENTIFICOS DE LA UNAM DESCUBRIERON Y LOGRARON DETERMINAR LA MORFOLOGIA DEL PRIMER FOSIL EN AMERI... more CIENTIFICOS DE LA UNAM DESCUBRIERON Y LOGRARON DETERMINAR LA MORFOLOGIA DEL PRIMER FOSIL EN AMERICA: UNA LANGOSTA DEL GENERO "PALINURUS PALACIOS", EL M S ANTIGUO LOCALIZADO EN EL MUNDO, CON 110 MILLONES DE ANOS. SE CONSIDERA QUE EN EL SITIO DEL HALLAZGO, UBICADO EN CHIAPAS, PUDO HABER COMENZADO LA EVOLUCION DE ESTA ESPECIE, ASI COMO EL ORIGEN DE VARIAS PLANTAS Y ANIMALES. FRANCISCO JAVIER VEGA VERA, DEL INSTITUTO DE GEOLOGIA, EXPLICO QUE EL FOSIL DE LA LANGOSTA -EN DOLOMITA LAMINAR (CANTERA)- FUE DESCUBIERTO EN CHIAPAS EN 1995, EN EL POBLADO DE EL ESPINAL, POR PALEONTOLOGOS DE LA FACULTAD DE CIENCIAS, EN PARTICULAR POR PEDRO GARCIA BARRERA. ESTABLECER LA ANTIGEDAD DE LA ESPECIE Y DE LA LOCALIDAD -110 MILLONES DE ANOS-, ASI COMO DETERMINAR QUE SE TRATABA DE UN GENERO DE LANGOSTA DESCONOCIDA QUE HABITABA EN EL CONTINENTE, SE LLEVO VARIOS ANOS DE INVESTIGACION DE DIVERSOS CIENTIFICOS DEL INSTITUTO, YA QUE HALLAZGOS PREVIOS DE ESTA SOLO SE HABIAN REGISTRADO EN AFRICA, PRECISO...
EL DOCTOR FRANCISCO JAVIER VEGA, INVESTIGADOR DEL INSTITUTO DE GEOLOGIA, INFORMO DE LOS HALLAZGOS... more EL DOCTOR FRANCISCO JAVIER VEGA, INVESTIGADOR DEL INSTITUTO DE GEOLOGIA, INFORMO DE LOS HALLAZGOS DE MUDAS FOSILES DE CANGREJO EN EL NOROESTE DE MONTERREY, CONCRETAMENTE LA "COSTACOPLUMA MEXICANA" QUE ES UNA DE LAS MAS RARAS DE ENCONTRAR DEBIDO A LAS DIFICULTADES QUE IMPLICA SU PRESERVACION. DIJO QUE CON ESTE HALLAZGO SE DA EL PRIMER REPORTE DE ESTA ESPECIE DE CANGREJOS EN LA PARTE SUR DE LO QUE ERA EL CONTIENENTE AMERICANO, CON ELLO SE PUEDE INFERIR LA PALEOGRAFIA DE ESE ENTONCES.
A new homolid crab Peedeehomola new genus, with Peedeehomola deanbogani n. gen., n. sp., is repor... more A new homolid crab Peedeehomola new genus, with Peedeehomola deanbogani n. gen., n. sp., is reported from the Late Cretaceous (late Maastrichtian) of the Rocky Point Member of the Peedee Formation (North Carolina). Peedeehomola deanbogani n. gen., n. sp. possesses peculiar characters, such as the pseudorostral spine as long as the rostrum, the two supraorbital spines directed forward and the prominent anterolateral spine directed outward, not shared with any known genus within the Homolidae.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2016
A new species of Prosopidae, Rathbunopon viai n. sp., is herein described, based on two specimens... more A new species of Prosopidae, Rathbunopon viai n. sp., is herein described, based on two specimens collected from lower Aptian deposits of Cuchía, Northern Spain. Examination of this new material allows us to garner a better understanding of the phylogeny and systematics of this genus during the Early Cretaceous. Additionally, the second occurrence of Mithracites vectensis (Homoloidea) is reported here from Aptian deposits in La Tejería de Josa, Southern, Spain.
Journal of South American Earth Sciences, 2015
Abstract Amber from the Campo La Granja mine in Chiapas, Mexico, is distinct from other sources o... more Abstract Amber from the Campo La Granja mine in Chiapas, Mexico, is distinct from other sources of amber in Chiapas. Campo La Granja amber has distinct layers created by successive flows of resin with thin layers of sand on most surfaces. Aquatic and semi-aquatic arthropods are commonly found. Together these pieces of evidence suggest an estuarine environment similar to modern mangrove communities. The aquatic crustaceans are the most intriguing aspect of the biota. A large number of ostracods have been found in the amber—many with their carapaces open, suggesting that they were alive and submerged in water at the time of entombment. The only known examples of brachyuran crabs preserved in amber are found in the Campo La Granja amber. Amphipods, copepods, isopods, and tanaids are also members of the crustacean fauna preserved in amber.
ABSTRACT Bulletin of the Mizunami Fossil Museum, no. 39 (2013), p. 39–45, 2 figs., 1 pl. © 2013, ... more ABSTRACT Bulletin of the Mizunami Fossil Museum, no. 39 (2013), p. 39–45, 2 figs., 1 pl. © 2013, Mizunami Fossil Museum Three species of crabs are here reported from the Lower Miocene Khari Nadi Formation at Matanomadh and Lakhpat sections, Western India. Philyra karkata new species is included. Palaeocarpilius cf. P. rugifer Stoliczka, 1871 is first reported from the Middle Eocene Fulra Limestone at Lakhpat section.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2013
Abundant concretions at two localities in central Colombia where the San Gil Inferior and San Gil... more Abundant concretions at two localities in central Colombia where the San Gil Inferior and San Gil Superior formations are exposed, have yielded numerous crustacean individuals, comprising one new genus Rathbunassa n. gen. (Callianassidae), two new species Joeranina colombiana n. sp., Planocarcinus johnjagti n. sp., and three further species. The following taxa are recorded: ?Paraxiopsis sp. (Axiidae), Rathbunassa aquilae (rAtHBun, 1935) n. comb. (Callianassidae), Joeranina kerri (Luque, FeLdmAnn, SCHweitzer, JArAmiLLo & CAmeron, 2012) n. comb., Joeranina colombiana n. sp. (Palaeocorystidae), Cenomanocarcinus vanstraeleni StenzeL, 1945 (Cenomanocarcinidae), and Planocarcinus johnjagti n. sp. (Necrocarcinidae). Based on ammonite evidence, the locality within the San Gil Inferior Formation is considered to be of late Aptian age, while the one exposing the San Gil Superior Formation is of middle Albian date. Joeranina kerri is found at both localities; in contrast Planocarcinus johnjagti n. sp. occurs exclusively in the upper Aptian, while the remainder of species are all from the middle Albian locality. The taxa reported herein add important data to the palaeobiodiversity and distribution of Cretaceous decapod crustaceans.
Journal of South American Earth Sciences, 2013
The portunoid crab Ophthalmoplax Rathbun, 1935, is known from late Cretaceous deposits of Africa ... more The portunoid crab Ophthalmoplax Rathbun, 1935, is known from late Cretaceous deposits of Africa and the Americas. A review of 76 specimens from many localities in North and South America reveals that the genus is represented by only two species d one in Africa (recently described) and the other in the Americas. Ophthalmoplax brasiliana (Maury, 1930) was distributed along the Atlantic and Gulf coasts of the Americas throughout the Maastrichtian d from Brazil to North Carolina. In early Maastrichtian deposits of North America (w69.0 Ma), the species is represented by local populations of medium-sized individuals, and by the late Maastrichtian (w67.0 Ma), populations of larger individuals became abundant. This size increase may be related to a decrease in ocean water temperatures. Populations of medium-sized individuals are found again in the latest Maastrichtian (w66.2 Ma), below strata with ejecta deposits in Coahuila, Mexico, and in the uppermost Owl Creek Formation, Mississippi. This size decrease is possibly linked to an increase in seawater temperature occurring just below the K/P boundary, when Ophthalmoplax became extinct.
Journal of Paleontology, 2014
The first Mesozoic thylacocephalans from the western hemisphere are documented from the Muhi Quar... more The first Mesozoic thylacocephalans from the western hemisphere are documented from the Muhi Quarry plattenkalk in the La Negra facies of the El Doctor Formation (Albian–Cenomanian), Zimapán Area, northwestern Hidalgo, central Mexico. They all are found in a single horizon at the base of the type section. These specimens represent two new genera and species, and a third undetermined species which likely also represents a new genus and species. Victoriacaris muhiensis is a shorted-bodied thylacocephalan with concave anterior and posterior notches as well as a beveled anterior spine. Polzia eldoctorensis is trapezoidal in outline with a rounded posteroventral corner. The third undetermined species is known only from one broken specimen, but has distinctive marginal spines that are not possessed by any other post-Cambrian thylacocephalan. The occurrence of such a diverse fauna of thylacocephalans markedly increases the diversity and geographic range of Cretaceous thylacocephalans, but ...
Nauplius, 2017
Our knowledge of fossil crustaceans from the tropics has increased considerably during recent dec... more Our knowledge of fossil crustaceans from the tropics has increased considerably during recent decades, thanks to novel findings and the reexamination of museum specimens. However, several previous records have
Journal of Paleontology, 2004
Mexfusus rotundicostatus new genus and species is a neogastropod of uncertain affinities from the... more Mexfusus rotundicostatus new genus and species is a neogastropod of uncertain affinities from the Late Cretaceous (Early Maastrichtian) Mexcala Formation of southern Mexico. It is characterized by strong, rounded, axial ribs, fine spinelets at the intersection of axial ribs and sharp spiral cords, subsutural cord, strong simple spiral cords, and an apparently smooth, glazed columellar lip. A possible second species is Peristernia conica Riedel, 1932 from the Coniacian of Cameroon.
Revista Brasileira de …, 2006
RESUMO-Neste trabalho são descritos, pela primeira vez, os peixes fósseis provenientes do Estado ... more RESUMO-Neste trabalho são descritos, pela primeira vez, os peixes fósseis provenientes do Estado de Guerrero, México. O material fóssil foi coletado em seis localidades do Cretáceo Superior (Turoniano-Maastrichtiano) pertencentes à Formação Mexcala. Os fósseis representam grupos de condrícties, incluindo dentes de Ptychodus mortoni, P. decurrens, Serratolamna serrata, Squalicorax sp. e Cretoxyrhina cf. mantelli, além de vértebras de lamniformes indeterminados. Os osteícties identificados incluem restos de ichthyodectiformes, Tselfatia sp., Enchodus sp., Pachyrhizodus cf. caninus, dercetídeos, assim como distintos ossos, dentes e escamas de teleósteos indeterminados. Esta contribuição representa o registro mais austral na América do Norte de peixes do Cretáceo Superior, a qual permite ampliar a distribução geográfica dos táxons mencionados, incluindo agora o extremo oeste do Mar de Tétis ou Paleo Golfo de México. Além disso, é registrada a descoberta mais recente (Maastrichtiano) de Ptychodus mortoni.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2015
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Papers by Fancisco J. Vega