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1.
Sci Rep ; 14(1): 317, 2024 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172381

RESUMO

The study of the large paraphyletic group of extinct 'palaeoniscoid' fishes has shed light on the diversity and evolutionary history of basal actinopterygians. However, only a little ontogenetic information about 'palaeoniscoids' is known because their records in the early stages of development are scarce. Here, we report on a growth series of 'palaeoniscoids' in the juvenile stage from the Upper Triassic Amisan Formation of South Korea. Fourteen specimens, including five counterpart specimens, represent a new taxon, Megalomatia minima gen. et sp. nov., exhibiting ontogeny and exceptional preservation with the eyes possibly containing the crystalline lens, the otoliths, and the lateral line canals without covering scales. This discovery allows us to discuss the adaptations and evolution of basal actinopterygians in more detail than before. The otoliths in situ of Megalomatia support the previous interpretation that basal actinopterygians have a sagitta as the largest otolith. The trunk lateral line canal, which runs under the scales instead of passing through them, represents a plesiomorphic gnathostome trait. Notably, the large protruded eyes suggest that Megalomatia probably has binocular vision, which would have played a significant role in targeting and catching prey with the primitive jaw structure. In addition, the firstly formed skeletal elements such as the jaws, pectoral girdle, and opercular series, and the posteroanterior pattern of squamation development are likely linked to the adaptation of young individuals to increase their viability for feeding, respiration, and swimming.


Assuntos
Fósseis , Arcada Osseodentária , Animais , Peixes , República da Coreia , Filogenia
2.
Sci Rep ; 14(1): 549, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38272887

RESUMO

Numerous non-avian dinosaurs possessed pennaceous feathers on their forelimbs (proto-wings) and tail. Their functions remain unclear. We propose that these pennaceous feathers were used in displays to flush hiding prey through stimulation of sensory-neural escape pathways in prey, allowing the dinosaurs to pursue the flushed prey. We evaluated the escape behavior of grasshoppers to hypothetical visual flush-displays by a robotic dinosaur, and we recorded neurophysiological responses of grasshoppers' escape pathway to computer animations of the hypothetical flush-displays by dinosaurs. We show that the prey of dinosaurs would have fled more often when proto-wings were present, especially distally and with contrasting patterns, and when caudal plumage, especially of a large area, was used during the hypothetical flush-displays. The reinforcing loop between flush and pursue functions could have contributed to the evolution of larger and stiffer feathers for faster running, maneuverability, and stronger flush-displays, promoting foraging based on the flush-pursue strategy. The flush-pursue hypothesis can explain the presence and distribution of the pennaceous feathers, plumage color contrasts, as well as a number of other features observed in early pennaraptorans. This scenario highlights that sensory-neural processes underlying prey's antipredatory reactions may contribute to the origin of major evolutionary innovations in predators.


Assuntos
Dinossauros , Animais , Dinossauros/anatomia & histologia , Membro Anterior/fisiologia , Estimulação Luminosa , Plumas , Evolução Biológica , Fósseis
3.
PeerJ ; 10: e13176, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35402094

RESUMO

Here we report a new articulated skeleton of Yamaceratops dorngobiensis (MPC-D 100/553) from the Khugenetjavkhlant locality at the Shine Us Khudag (Javkhlant Formation, ?Santonian-Campanian) of the eastern Gobi Desert, Mongolia, which represents the first substantially complete skeleton and the first juvenile individual of this taxon. The specimen includes a nearly complete cranium and large portions of the vertebral column and appendicular skeleton. Its skull is about 2/3 the size of the holotype specimen, based on mandibular length. Its juvenile ontogenetic stage is confirmed by multiple indicators of skeletal and morphological immaturity known in ceratopsians, such as the long-grained surface texture on the long bones, the smooth external surface on the postorbital, open neurocentral sutures of all caudal vertebrae, a large orbit relative to the postorbital and jugal, the low angle of the lacrimal ventral ramus relative to the maxillary teeth row, narrow frontal, and straight ventral edge of the dentary. Osteohistological analysis of MPC-D 100/553 recovered three lines of arrested growth, implying around 3 years of age when it died, and verified this specimen's immature ontogenetic stage. The specimen adds a new autapomorphy of Yamaceratops, the anteroventral margin of the fungiform dorsal end of the lacrimal being excluded from the antorbital fossa. Furthermore, it shows a unique combination of diagnostic features of some other basal neoceratopsians: the ventrally hooked rostral bone as in Aquilops americanus and very tall middle caudal neural spines about or more than four times as high as the centrum as in Koreaceratops hwaseongensis, Montanoceratops cerorhynchus, and Protoceratops andrewsi. The jugal with the subtemporal ramus deeper than the suborbital ramus as in the holotype specimen is also shared with A. americanus, Liaoceratops yanzigouensis, and juvenile P. andrewsi. Adding 38 new scorings into the recent comprehensive data matrix of basal Neoceratopsia and taking into account the ontogenetically variable characters recovered Y. dorngobiensis as the sister taxon to Euceratopsia (Leptoceratopsidae plus Coronosauria). A second phylogenetic analysis with another matrix for Ceratopsia also supported this position. The new phylogenetic position of Y. dorngobiensis is important in ceratopsian evolution, as this taxon represents one of the basalmost neoceratopsians with a broad, thin frill and hyper-elongated middle caudal neural spines while still being bipedal.


Assuntos
Dinossauros , Dente , Animais , Filogenia , Mongólia , Crânio/anatomia & histologia , Dente/anatomia & histologia , Dinossauros/anatomia & histologia , Bochecha
4.
Artigo em Inglês | MEDLINE | ID: mdl-34444073

RESUMO

Governments have designated national parks to protect the natural environment against ecosystem destruction and improve individuals' emotional and recreational life. National parks enhance environment-friendly awareness by conducting ecotourism activities and individuals with environment-friendly awareness are inclined to continue to visit national parks as ecotourism destinations. The New Environmental Paradigm (NEP) is a widely used measure of environmental concern, suitable for measuring the environment-friendly attitude and revisit intention of visitors of national parks. Therefore, the study carried out structural equation modeling (SEM) to investigate the relationship between the NEP, national park conservation consciousness and environment-friendly behavioral intention. Based on the results, an implication is presented to induce national parks to cultivate individual environment-friendly awareness and for visitors to pursue sustainable, environment-friendly tourism behavior. The findings indicate that national parks are to expand educational programs and facilities for eco-tourists visiting national parks to maintain a balanced relationship between themselves and nature and have a strong environmental awareness to preserve the natural environment.


Assuntos
Ecossistema , Parques Recreativos , Atitude , Conservação dos Recursos Naturais , Humanos , Turismo
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