Palynological Investigations of the Miocene sediments from Murree formation of Pakistan: Evidence for Palaeoenvironment and Palaeoclimate interpretations.

The present study was carried out to investigate the palynoflora of Murree formation using microscopic techniques to understand the climatic changes and vegetation's evolution. In this palynological study, 31 samples were collected, analyzed, and then identified as palynomorphs using different previous published literature. The results of this study will be described in terms of the evolutionary history of plants and the depositional environment of the reported taxa in the study area. The botanical affinities and systematic description of the taxa were examined using light and scanning electron microscopy. The floral record identified Asteraceae as the dominant family and Pinus as a genus. Most of angiosperms i.e Fabaceae and Poaceae, have a poor fossil record but have an abundant palynological record in the study area. The highest polar diameter (75.75 µm), colpus length (34.5 µm) and colpus width (31 µm) were examined for the Convolvulus. Most of the taxa explained here had a wide geographical occurrence in Southeast Asia and show the abundance of angiosperms in the Miocene epoch. The palynological record of Holocene samples is important to know about the vegetation's origin and environmental fluctuations in the study area.

The southwesternmost record of late Silurian (Pridolian) early land plants of Gondwana.

The Silurian-Devonian transition played a crucial role in the development of early terrestrial ecosystems due to the rapid diversification of early vascular plants. However, records of Pridolian plants in western Gondwana are scarce, limited to outcrops located in southern Bolivia. In this contribution, an association of fossil plants housed in the Rinconada Formation is presented. This association corresponds to primitive fossil flora with reproductive structures and sterile axes linked to basal tracheophytes. The fossil assemblage is composed of Aberlemnia caledonica, Caia langii Cooksonia cf. cambrensis, C. paranensis, C. cf. pertoni, Hostinella sp, Cf. Isidrophyton sp, Salopella marcensis, Steganoteca striata, two morphotypes of doubtful taxonomy, and graptolites colonies. The association between flora remains and graptolites, represents a parautochthonous assemblage in an inner marine platform, dominated by gravity flows. This record has paleophytogeographic importance indicating the extension of the northwest Gondwana-southern Laurusia unit to more southern areas of Gondwana. This expansion would have been favored by the post-glacial climatic improvement of the Late Silurian, together with a great radiation capacity and environmental flexibility of the flora. Furthermore, the biochron is extended of three taxa (A. caledonica, C. paranensis and Cf. Isidrophyton sp) first known from the Lochkovian, to the Pridoli.

Overview of computational methods in taphonomy based on the combination of bibliometric analysis and natural language.

Artificial intelligence tools are new in taphonomy and are growing fast. They are being used mainly to investigate bone surface marks. In order to investigate this subject, a bibliometric study was made to understand the growing rate of this intersectional field, the future, and gaps in the field until now. From Scopus and Google Scholar metadata, graphs were made to describe the data, and inferential statistics were made by regression with the Ordinary Least Squares method. Exploratory analysis with word clouds, topic modeling, and natural language processing with Latent Dirichlet Allocation as a method were also made using the entire corpus from the papers. From the first register until 2023, we found eight articles in Scopus and 32 in Google Scholar; the majority of the studies and the most cited were from Spain. The studies are growing fast from 2016 to 2018, and the regression shows that growth can be maintained in the coming years. Exploratory analysis shows the most frequent words are marks, models, data, and bone. Topic modeling shows that the studies are highly concentrated on similar problems and the tools to solve them, revealing that there is much more to explore with computational tools in taphonomy and paleontology as well.

Anthropic cut marks in extinct megafauna bones from the Pampean region (Argentina) at the last glacial maximum.

The initial peopling of South America is a topic of intense archaeological debate. Among the most contentious issues remain the nature of the human-megafauna interaction and the possible role of humans, along with climatic change, in the extinction of several megamammal genera at the end of the Pleistocene. In this study, we present the analysis of fossil remains with cutmarks belonging to a specimen of Neosclerocalyptus (Xenarthra, Glyptodontidae), found on the banks of the Reconquista River, northeast of the Pampean region (Argentina), whose AMS 14C dating corresponds to the Last Glacial Maximum (21,090-20,811 cal YBP). Paleoenvironmental reconstructions, stratigraphic descriptions, absolute chronological dating of bone materials, and deposits suggest a relatively rapid burial event of the bone assemblage in a semi-dry climate during a wet season. Quantitative and qualitative analyses of the cut marks, reconstruction of butchering sequences, and assessments of the possible agents involved in the observed bone surface modifications indicate anthropic activities. Our results provide new elements for discussing the earliest peopling of southern South America and specifically for the interaction between humans and local megafauna in the Pampean region during the Last Glacial Maximum.

Dispersal of Late Triassic clam shrimps across Pangea linking northwestern Gondwana and central Pangea rift basins.

Clam shrimps are a group of freshwater crustaceans who prospered during the Late Triassic. They were abundant in lacustrine sedimentary records of continental basins distributed throughout Pangea during this time. However, they show significant taxonomic differences between the clamp shrimp faunas from the rift basins of central Pangea and the southern Gondwanan basins. In this contribution, we show new fossil clam shrimp assemblages from the lacustrine sedimentary successions of the Eastern Cordillera of Colombia (the Bocas and Montebel formations), providing information on the Late Triassic species that inhabited the northwestern Gondwana basins. This study demonstrates that the basins of northwestern Gondwana shared Norian clamp shrimp species with rift basins of central Pangea and differed in their faunas with the basins of the southern portion of Gondwana. In addition, the Late Triassic clam shrimps paleobiogeographic distribution reflects the dispersal of this fauna throughout fluvial-lacustrine environments established in the rift valleys along the central Pangea. Therefore, the rift valleys produced during the early fragmentation of central Pangea could have acted as corridors for dispersion. Simultaneously, rift valleys also provided paleobiogeographic barriers that isolated the central Pangea clam shrimp faunas from southern Gondwana.

Dawn of diverse shelled and carbonaceous animal microfossils at ~ 571 Ma.

The Ediacaran-Cambrian transition documents a critical stage in the diversification of animals. The global fossil record documents the appearance of cloudinomorphs and other shelled tubular organisms followed by non-biomineralized small carbonaceous fossils and by the highly diversified small shelly fossils between ~ 550 and 530 Ma. Here, we report diverse microfossils in thin sections and hand samples from the Ediacaran Bocaina Formation, Brazil, separated into five descriptive categories: elongate solid structures (ES); elongate filled structures (EF); two types of equidimensional structures (EQ 1 and 2) and elongate hollow structures with coiled ends (CE). These specimens, interpreted as diversified candidate metazoans, predate the latest Ediacaran biomineralized index macrofossils of the Cloudina-Corumbella-Namacalathus biozone in the overlying Tamengo Formation. Our new carbonate U-Pb ages for the Bocaina Formation, position this novel fossil record at 571 ± 9 Ma (weighted mean age). Thus, our data point to diversification of metazoans, including biomineralized specimens reminiscent of sections of cloudinids, protoconodonts, anabaritids, and hyolithids, in addition to organo-phosphatic surficial coverings of animals, demonstrably earlier than the record of the earliest known skeletonized metazoan fossils.

Exploring the effects of weighting against homoplasy in genealogies of palaeontological phylogenetic matrices.

Although simulations have shown that implied weighting (IW) outperforms equal weighting (EW) in phylogenetic parsimony analyses, weighting against homoplasy lacks extensive usage in palaeontology. Iterative modifications of several phylogenetic matrices in the last decades resulted in extensive genealogies of datasets that allow the evaluation of differences in the stability of results for alternative character weighting methods directly on empirical data. Each generation was compared against the most recent generation in each genealogy because it is assumed that it is the most comprehensive (higher sampling), revised (fewer misscorings) and complete (lower amount of missing data) matrix of the genealogy. The analyses were conducted on six different genealogies under EW and IW and extended implied weighting (EIW) with a range of concavity constant values (k) between 3 and 30. Pairwise comparisons between trees were conducted using Robinson-Foulds distances normalized by the total number of groups, distortion coefficient, subtree pruning and regrafting moves, and the proportional sum of group dissimilarities. The results consistently show that IW and EIW produce results more similar to those of the last dataset than EW in the vast majority of genealogies and for all comparative measures. This is significant because almost all of these matrices were originally analysed only under EW. Implied weighting and EIW do not outperform each other unambiguously. Euclidean distances based on a principal components analysis of the comparative measures show that different ranges of k-values retrieve the most similar results to the last generation in different genealogies. There is a significant positive linear correlation between the optimal k-values and the number of terminals of the last generations. This could be employed to inform about the range of k-values to be used in phylogenetic analyses based on matrix size but with the caveat that this emergent relationship still relies on a low sample size of genealogies.

A remarkable assemblage of petroglyphs and dinosaur footprints in Northeast Brazil.

The Serrote do Letreiro Site, found on the northwest periphery of the Sousa Basin, Brazil, presents a remarkable convergence of paleontological and archaeological elements. It is constituted of sub-horizontal "lajeiros", or rock outcrops, intermingled with endemic Caatinga vegetation. The three prominent outcrops feature fossilized footprints of theropod, sauropod, and iguanodontian dinosaurs from the Early Cretaceous Period. Adjacent to these dinosaur tracks, indigenous petroglyphs adorn the surface. The petroglyphs, mainly characterized by circular motifs, maintain a striking resemblance to other petroglyphs found in the states of Paraíba and Rio Grande do Norte. This study primarily endeavors to delineate the site's major characteristics while concentrating on the relationship between the dinosaur footprints and the petroglyphs. It concurrently assesses the preservation status of this invaluable record, shedding light on its implications for the realms of paleontology, archaeology, and cultural heritage studies.

Invertebrados (Echinodermata, Brachiopoda, Bryozoa, Cnidaria, Porifera) del Carbonífero de Sierra Santa Teresa, Sonora, México: Consideraciones paleoecológicas y paleogeográficas / Invertebrates (Echinodermata, Brachiopoda, Bryozoa, Cnidaria, Porifera) from the Carboniferous of Sierra Santa Teresa, Sonora, Mexico: Paleoecological and paleogeographic considerations

Resumen Introducción: La Sierra Santa Teresa se encuentra a 20 km al sureste de Hermosillo en la región central del estado de Sonora, México. Los estratos sedimentarios corresponden principalmente a textura de piedra caliza, mudstone, wackestone y packstone del Paleozoico superior. La biota está representada por crinoideos de las morfoespecies Baryschyr anosus, Cyclocaudex insaturatus, Floricyclus angustimargo, Cyclocion distictus, Lamprosterigma erathense y Preptopremnum rugosum en asociación con algas, foraminíferos fusulínidos, esponjas coralinas (Chaetetes sp), corales solitarios (Lophophyllidium sp., Fomichevella sp.), briozoos fenestélidos (Archimedes stoyanowi) y braquiópodos (Antiquatonia sp.). Objetivo: El objetivo principal de este estudio es dar a conocer la composición biótica de la Sierra Santa Teresa y sus consideraciones paleoecológicas y paleogeográficas. Métodos: En este estudio se sintetiza la información sobre las principales taxas recolectadas en afloramientos del Carbonífero de la Sierra, Santa Teresa. Resultados: La distribución de la biota, y particularmente de las morfoespecies de crinoideos, permitió hacer correlaciones paleobiogeográficas con otras localidades del Misisípico-Pensilvánico de México y de distintas regiones de los Estados Unidos de América, principalmente en Texas, Colorado, Illinois y Oklahoma, que se encontraban ubicadas al suroeste del Cratón norteamericano. Conclusiones: Se considera que el paleoambiente inferido con base en los registros paleontológicos de la Sierra Santa Teresa se trataba de mares someros que permitieron el desarrollo de comunidades de crinoideos, así como otros invertebrados como esponjas coralinas, corales solitarios, briozoos fenestélidos y braquiópodos, con un rango estratigráfico del Misisípico Medio-Superior (Chesteriano) al Pensilvánico Medio (Desmoinesiano).

Abstract Introduction: The Sierra Santa Teresa is located 20 km southeast of Hermosillo in the central region of Sonora state, Mexico. The sedimentary strata mainly correspond to limestone, mudstone, wackestone and packstone texture, from the upper Paleozoic. The biota is represented by crinoids of the morphospecies Baryschyr anosus, Cyclocaudex insaturatus, Floricyclus angustimargo, Cyclocion distictus, Lamprosterigma erathense, Preptopremnum rugosum in association with algae, fusulinid foraminifera, coralline sponges (Chaetetes sp.), solitary corals (Lophophyllidium sp., Fomichevella sp.), fenestellid bryozoans (Archimedes stoyanowi), and brachiopods (Antiquatonia sp.). Objective: The principal aim of this study is to analyze the biotic composition in the Sierra Santa Teresa and its paleoecological and paleogeographical considerations. Methods: In this study we synthetize information about the principal taxa collected in outcrops of the Carboniferous of the Sierra, Santa Teresa. Results: The distribution of the biota, and particularly the crinoid morphospecies, allowed paleobiogeographical correlations to be made with other Mississippian-Pennsylvanian localities of Mexico and different regions of the United States of America in Texas, Colorado, Illinois and Oklahoma, which were located in the southwestern of the North American Craton. Conclusions: It is considered that the paleoenvironment inferred based on the paleontological records of the Sierra Santa Teresa were shallow seas that allowed the development of communities of crinoids, as well as other invertebrates such as coralline sponges, solitary corals, fenestellid bryozoans and brachiopods, with a range stratigraphic from the Middle-Upper Mississippian (Chesterian) to the Middle Pennsylvanian (Desmoinesian).

Taphonomy of harpy eagle predation on primates and other mammals.

The goal of this study is to provide a taphonomic analysis of bone fragments found in harpy eagle nests in the Brazilian Amazonia, utilizing the largest sample of prey remains collected to date. Harpy eagle kill samples were collected from nine nests, between June 2016 and December 2020 in Mato Grosso, Brazil. We identified the specimens, calculated the number of identified specimens (NISP) and minimum number of individuals (MNI). These metrics were used to estimate bone survivability and fragmentation. A total of 1661 specimens (NISP) were collected, representing a minimum number of 234 individuals (MNI). We identified at least nine species of primates, which represent 63.8% of the individuals in the kill sample. Harpy eagles preyed mostly on the medium-sized capuchin and bearded saki monkeys (28.2% of the MNI), and two-toed sloths (17.7% of the MNI). The large woolly monkeys also represented a significant portion of the sample (11.5% of the MNI). Three distinct patterns of bone survivability were found, one characterizing two-toed sloths, another characterizing medium-sized monkeys, and a third typical of woolly monkeys. We conclude that harpy eagle predation leaves an identifiable signature on the prey with a bone survivability pattern specific to each taxon. The intertaxon variations observed in the taphonomic signatures of harpy eagle kills should be taken into account when evaluating the potential influence of these raptors as accumulators of bone material in both paleontological and neontological assemblages.

Bone histology supports gregarious behavior and an early ontogenetic stage to Decuriasuchus quartacolonia (Pseudosuchia: Loricata) from the Middle-Late Triassic of Brazil.

Decuriasuchus quartacolonia is a middle-sized basal "rauisuchian" (Pseudosuchia, Loricata) from the Triassic beds of Brazil, whose original description was based on 10 specimens of equivalent size found in aggregation. In this contribution, we explore the osteohistology of its appendicular bones and a rib, aiming to infer growth patterns and ontogeny. In all analyzed bones (except in the rib) from three individuals, we found fibrolamellar bone (FLB) throughout the cortices, a pattern shared with other histologically sampled basal loricatans. We found evidence that suggests an early ontogenetic stage for all studied specimens: absence of secondary osteons, lack of transition from an inner highly vascularized FLB matrix to a poor vascularized parallel-fibred bone, one line of arrested growth, open vascular canals in the external surface of the cortex and absence of an external fundamental system. In addition, we observed that the neurocentral sutures in the caudal to cervical vertebrae of the holotype are unfused, strongly suggesting that these individuals were not skeletally mature, as had been previously assumed. In addition, our data support the prior hypothesis that Decuriasuchus is the oldest-known archosaur to show evidence of gregarious behavior and adds a probable cause of this as a strategy to obtain food and avoid predation until becoming independent as adults. Furthermore, our results open the possibility that Decuriasuchus may represent an earlier growth stage of the larger Prestosuchus chiniquensis, with two specimens recovered from the same stratigraphic level and paleontological site. Since the adult form of Decuriasuchus remains unknown, a deeper anatomical study is needed to discuss the validity of the species. This study case exemplifies the importance of paleohistology as an essential complementary tool to describe a new morphospecies in vertebrate paleontology.

Francisco Javier Muñiz. Cirujano de guerra / Francisco Javier Muñiz. War Surgeon

Francisco Javier Muñiz nació en Monte Grande en 1795 y se graduó de médico en la Facultad de Medicina de la Universidad de Buenos Aires en 1822. Además de la medicina y la paleontología, Muñiz se desempeñó como cirujano de guerra en la guerra con el Brasil y en la guerra de la Triple Alianza. En 1871, encontrándose jubilado, se ofrece como voluntario en la lucha contra la epidemia de fiebre amarilla que asoló a la ciudad de Buenos Aires provocando 14.467 muertos. Muñiz falleció el 8 de abril de 1871 en cumplimiento del deber, contagiado de fiebre amarilla. Médico, periodista, paleontólogo, descubridor de la vacuna nativa contra la viruela y realizador de apuntes de lingüística, Francisco Javier Muñiz, representa uno de los grandes ejemplos para la sociedad argentina. (AU)

Francisco Javier Muñiz was born in Monte Grande in 1795 and graduated as a physician from the Faculty of Medicine of the University of Buenos Aires in 1822. In addition to medicine and paleontology, Muñiz served as a military surgeon in the War with Brazil and in the War of the Triple Alliance. In 1871, when he was retired, he volunteered to fight the yellow fever epidemic that devastated the city of Buenos Aires, causing 14,467 deaths. Muñiz died in the line of duty on April 8, 1871, infected with yellow fever. Doctor, journalist, paleontologist, discoverer of the native vaccine against smallpox and linguistic note-taker, Francisco Javier Muñiz is one of the great examples for Argentinian society. (AU)

A new species of Comahuesuchus Bonaparte, 1991 (Crocodyliformes: Notosuchia) from the Upper Cretaceous of Neuquén, Lake Barreales, Patagonia, Argentina.

Notosuchian crocodyliforms were major components of the South American Cretaceous biota and, for over 125 years, paleontological fieldwork in this continent recovered several well-preserved fossils of these animals. They are largely recognized for terrestrial life and specialized feeding habits, frequently presenting bizarre taxa such as Comahuesuchus. A new species, Comahuesuchus bonapartei n. sp. (MUCPv 597; cast MN), is described from geological strata of Sierra Barrosa Formation (Upper Turonian) and Portezuelo Formation (Lower Coniacian) of Lake Barreales, Patagonia, Argentina. The new fossil comprises a right dentary bone that shares important and unique anatomical features with specimens of Comahuesuchus brachybuccalis, such as the presence of a well-marked shelf on the lateral surface of the bone; a flat, low, and wide mandibular symphysis; an enlarged, labiolingually compressed caniniform tooth at caudal position in the dentary; the presence of serrated mesial and distal carinae in the caniniform with a faceted labial surface, and the absence or extremely reduction in number of the postcaniniform dentition. C. bonapartei differs from C. brachybuccalis in having individual dentary alveoli, rather a dentition set in groove. Phylogenetic analyses support a sister-relationship between both species, which are well nested within notosuchians.

Historiographical approaches to biogeography: a critical review.

We performed a critical review of the historiographical studies on biogeography. We began with the pioneering works of Augustin and Alphonse de Candolle. Then, we analyzed the historical accounts of biogeography developed by (1) Martin Fichman and his history on the extensionism-permanentism debate; (2) Gareth Nelson and his critique of the Neo-Darwinian historiography of biogeography; (3) Ernst Mayr, with his dispersalist viewpoint; (4) Alan Richardson, who wrote a microhistory on the biogeographic model constructed by Darwin; (5) Michael Paul Kinch and the ideas discussed in the 19th century about the geographical distribution of living beings; (6) Janet Browne, who highlighted the importance of the pre-Darwinian naturalists; (7) Peter Bowler, who focused mainly on the influence of paleontology on biogeography; (8) James Larson, who looked into the practices of the naturalists of Northern Europe in the late 18th century; and (9) Malte Ebach, who like Larson, was more interested in analysing the practices rather than the ideas of naturalists who studied the geographical distribution of organisms. Finally, these works are compared with each other. There has not been a dominant paradigm in the construction of historical narratives of biogeography; however, they provide a useful context for understanding problems of biogeography that continue to be debated to this day.

Taphonomy of the teleost Tselfatia formosa Arambourg, 1943 from Vallecillo, NE Mexico.

The platy limestone deposit of Vallecillo in northeastern Mexico is dated to the early-middle Turonian (Late Cretaceous) and known to contain a variety of well-preserved vertebrate fossils. One of the most common fish species is the teleost Tselfatia formosa. A review of 149 individuals reveals the presence of two types of body shapes (diamond-shaped and torpedo-shaped individuals) which is interpreted as sexual shape dimorphism (SSD). A unimodal size distribution illustrates a dominance of diamond-shaped specimens, but both body shape types are present in small (young) and big sized (old) individuals. The abundance of well-articulated and complete specimens suggests that T. formosa populated deep levels of the water column, which excluded buoyancy and flotation as well as carcass disintegration near the surface. The reconstruction of the dorsal and anal fins suggests the presence of a membrane between each fin ray and allows for ecological comparison of T. formosa with modern fan fishes.

Osteology and reassessment of Dineobellator notohesperus, a southern eudromaeosaur (Theropoda: Dromaeosauridae: Eudromaeosauria) from the latest Cretaceous of New Mexico.

Dromaeosaurids (Theropoda: Dromaeosauridae), a group of dynamic, swift predators, have a sparse fossil record, particularly at the end of the Cretaceous Period. The recently described Dineobellator notohesperus, consisting of a partial skeleton from the Upper Cretaceous (Maastrichtian) of New Mexico, is the only diagnostic dromaeosaurid to be recovered from the latest Cretaceous of the southwestern United States. Reinterpreted and newly described material include several caudal vertebrae, portions of the right radius and pubis, and an additional ungual, tentatively inferred to be from manual digit III. Unique features, particularly those of the humerus, unguals, and caudal vertebrae, distinguish D. notohesperus from other known dromaeosaurids. This material indicates different physical attributes among dromaeosaurids, such as use of the forearms, strength in the hands and feet, and mobility of the tail. Several bones in the holotype exhibit abnormal growth and are inferred to be pathologic features resulting from an injury or disease. Similar lengths of the humerus imply Dineobellator and Deinonychus were of similar size, at least regarding length and/or height, although the more gracile nature of the humerus implies Dineobellator was a more lightly built predator. A new phylogenetic analysis recovers D. notohesperus as a dromaeosaurid outside other previously known and named clades. Theropod composition of the Naashoibito Member theropod fauna is like those found in the more northern Late Cretaceous North American ecosystems. Differences in tooth morphologies among recovered theropod teeth from the Naashoibito Member also implies D. notohesperus was not the only dromaeosaurid present in its environment.

Ice Age megafauna rock art in the Colombian Amazon?

Megafauna paintings have accompanied the earliest archaeological contexts across the continents, revealing a fundamental inter-relationship between early humans and megafauna during the global human expansion as unfamiliar landscapes were humanized and identities built into new territories. However, the identification of extinct megafauna from rock art is controversial. Here, we examine potential megafauna depictions in the rock art of Serranía de la Lindosa, Colombian Amazon, that includes a giant sloth, a gomphothere, a camelid, horses and three-toed ungulates with trunks. We argue that they are Ice Age rock art based on the (i) naturalistic appearance and diagnostic morphological features of the animal images, (ii) late Pleistocene archaeological dates from La Lindosa confirming the contemporaneity of humans and megafauna, (iii) recovery of ochre pigments in late Pleistocene archaeological strata, (iv) the presence of most megafauna identified in the region during the late Pleistocene as attested by archaeological and palaeontological records, and (v) widespread depiction of extinct megafauna in rock art across the Americas. Our findings contribute to the emerging picture of considerable geographical and stylistic variation of geometric and figurative rock art from early human occupations across South America. Lastly, we discuss the implications of our findings for understanding the early human history of tropical South America. This article is part of the theme issue 'Tropical forests in the deep human past'.

Smaller fish species in a warm and oxygen-poor Humboldt Current system.

Climate change is expected to result in smaller fish size, but the influence of fishing has made it difficult to substantiate the theorized link between size and ocean warming and deoxygenation. We reconstructed the fish community and oceanographic conditions of the most recent global warm period (last interglacial; 130 to 116 thousand years before present) by using sediments from the northern Humboldt Current system off the coast of Peru, a hotspot of small pelagic fish productivity. In contrast to the present-day anchovy-dominated state, the last interglacial was characterized by considerably smaller (mesopelagic and goby-like) fishes and very low anchovy abundance. These small fish species are more difficult to harvest and are less palatable than anchovies, indicating that our rapidly warming world poses a threat to the global fish supply.