EVOLUTIONARY PROCESSES IN THE FOSSIL RECORD: PATAGONIA AS A CASE STUDY

2017 ◽  
Author(s):  
Maria A. Gandolfo ◽  
◽  
Maria C. Zamaloa
Keyword(s):  
Fossil Record ◽  
Evolutionary Processes

COEVALNESS OF INSECT TRACE FOSSILS AND TRACE-BEARING ROCKS, A CASE STUDY FROM THE PLIO?-PLEISTOCENE OF SW SPAIN

Palaios ◽  
2021 ◽  
Vol 36 (3) ◽  
pp. 115-121
Author(s):  
EDUARDO MAYORAL ◽  
JORGE F. GENISE ◽  
FRANCISCO J. RODRÍGUEZ-TOVAR ◽  
ANA SANTOS
Keyword(s):  
Fossil Record ◽  
Field Research ◽  
Sw Spain ◽  
Modern Age ◽  
Different Types ◽  
The Matrix ◽  
Time Gap

ABSTRACT Plio?-Pleistocene outcrops located at the southwestern edge of the Guadalquivir Basin in the area of Lepe (Huelva, Spain) provide an interesting example for studying the contemporaneity of traces with the rocks that contain them. Two different types of cells compatible with the ichnogenera Celliforma (Type 1) and Palmiraichnus (Type 2) were found in these outcrops. Their walls were constructed with the same material as the matrix and our first research in the area showed no extant bees producing them suggesting that they were coeval with the trace-bearing rocks. The case of the “Palmiraichnus-like” Type 2 cells was misleading because of its similarity with Palmiraichnus described from the region in the Canary Islands and Balearic Archipelago (Spain). Two determining features were vital in clarifying this first appearance. In the Palmiraichnus-like cells we found remains of a larval cocoon in one cell that could be dated by C14, giving a modern age. In the Celliforma-like cells more field research in the area allow us to observe extant bees nesting in these rocks in autumn. Ichnological literature show a few cases of asynchronies involving extant traces found mostly in Paleozoic and Mesozoic rocks. In contrast, the case presented herein indicates the time gap between the bearing rocks and the Lepe traces was shorter (ca. 12 ky–2.6 My), enhancing the similarity of traces and rocks and thus their potential coevalness. This case may serve as a warning about other potential examples in the fossil record in which relatively short asynchronies between traces and paleosols exist.

scholarly journals Taxonomic and conservation implications of ecological speciation in Nesospiza buntings on Tristan da Cunha

2008 ◽  
Vol 18 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Peter G. Ryan
Keyword(s):  
Species Conservation ◽  
Natural Populations ◽  
Morphological Diversity ◽  
Ecological Speciation ◽  
Conservation Priority ◽  
Evolutionary Processes ◽  
Natural Processes ◽  
Tristan Da Cunha ◽  
Conservation Implications

AbstractIn addition to protecting species, conservation also includes the maintenance of evolutionary processes, but this aspect is often overlooked. Nesospiza buntings provide a good case study of the need to conserve evolutionary processes. They are endemic to the South Atlantic Tristan da Cunha archipelago, and traditionally have been treated as two species, with each having different subspecies on Nightingale and Inaccessible Islands. Both species are listed as Vulnerable because of their small ranges (<20 km2) and the threat posed by the possible introduction of alien organisms such as mice or rats. The two species differ markedly in size, especially bill size, related to dietary differences. However, recent research suggests that morphological diversity evolved independently on Nightingale and Inaccessible Islands, necessitating a revision of the taxonomy within the genus. I recommend that five taxa be recognized, with two endemic to Nightingale and three to Inaccessible Island. N. wilkinsi and N. questi on Nightingale are well-defined species, but there is considerable hybridization between taxa on Inaccessible Island. These three taxa may be incipient species, but are perhaps best treated as subspecies: N. acunhae acunhae, N. a. dunnei and N. a. fraseri (nom. nov.). All three species qualify as threatened, with N. acunhae and N. questi Vulnerable and N. wilkinsi Endangered. With fewer than 200 individuals, N. wilkinsi has one of the smallest natural populations of any bird. A reassessment of its population size is a conservation priority, following the 2001 storm that damaged many Phylica trees on Nightingale Island. Improved biosecurity quarantine measures are also needed for Nightingale Island. Care should be taken not to disrupt the natural processes occurring among bunting taxa on Inaccessible Island.

scholarly journals The importance of sampling standardization for comparisons of insect herbivory in deep time: a case study from the late Palaeozoic

2018 ◽  
Vol 5 (3) ◽  
pp. 171991 ◽  
Author(s):  
Sandra R. Schachat ◽  
Conrad C. Labandeira ◽  
S. Augusta Maccracken
Keyword(s):  
Surface Area ◽  
Fossil Record ◽  
Insect Herbivory ◽  
Ecological Factors ◽  
Published Data ◽  
Deep Time ◽  
Leaf Surface Area ◽  
Number Of Leaves ◽  
The Impact

Sampling standardization has not been fully addressed for the study of insect herbivory in the fossil record. The effects of sampling within a single locality were explored almost a decade ago, but the importance of sampling standardization for comparisons of herbivory across space and time has not yet been evaluated. Here, we present a case study from the Permian in which we evaluate the impact of sampling standardization on comparisons of insect herbivory from two localities that are similar in age and floral composition. Comparisons of insect damage type (DT) diversity change dramatically when the number of leaves examined is standardized by surface area. This finding suggests that surface area should always be taken into account for comparisons of DT diversity. In addition, the three most common metrics of herbivory—DT diversity, proportion of leaves herbivorized and proportion of leaf surface area herbivorized—are inherently decoupled from each other. The decoupling of the diversity and intensity of insect herbivory necessitates a reinterpretation of published data because they had been conflated in previous studies. Future studies should examine the divergent ecological factors that underlie these metrics. We conclude with suggestions to guide the sampling and analysis of herbivorized leaves in the fossil record.

scholarly journals A new hynobiid-like salamander (Amphibia, Urodela) from Inner Mongolia, China, provides a rare case study of developmental features in an Early Cretaceous fossil urodele

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2499 ◽  
Author(s):  
Jia Jia ◽  
Ke-Qin Gao
Keyword(s):  
Early Cretaceous ◽  
Inner Mongolia ◽  
Fossil Record ◽  
Rare Case ◽  
Posterior Border ◽  
Fossil Species ◽  
Developmental Patterns ◽  
Developmental Features ◽  
New Discovery

A new fossil salamander,Nuominerpeton aquilonaris(gen. et sp. nov.), is named and described based on specimens from the Lower Cretaceous Guanghua Formation of Inner Mongolia, China. The new discovery documents a far northern occurrence of Early Cretaceous salamanders in China, extending the geographic distribution for the Mesozoic fossil record of the group from the Jehol area (40th–45th parallel north) to near the 49th parallel north. The new salamander is characterized by having the orbitosphenoid semicircular in shape; coracoid plate of the scapulocoracoid greatly expanded with a convex ventral and posterior border; ossification of two centralia in carpus and tarsus; and first digit being about half the length of the second digit in both manus and pes. The new salamander appears to be closely related to hynobiids, although this inferred relationship awaits confirmation by research in progress by us on a morphological and molecular combined analysis of cryptobranchoid relationships. Comparison of adult with larval and postmetamorphic juvenile specimens provides insights into developmental patterns of cranial and postcranial skeletons in this fossil species, especially resorption of the palatine and anterior portions of the palatopterygoid in the palate and the coronoid in the mandible during metamorphosis, and postmetamorphic ossification of the mesopodium in both manus and pes. Thus, this study provides a rare case study of developmental features in a Mesozoic salamander.

Frozen in Time

2011 ◽  
Author(s):  
Jeffrey D Stilwell ◽  
John A Long
Keyword(s):  
Plant Communities ◽  
Fossil Record ◽  
Environmental Changes ◽  
Polar Ice ◽  
Comprehensive Overview ◽  
The Real ◽  
Past Time ◽  
Remote Sites

No other continent on Earth has undergone such radical environmental changes as Antarctica. In its transition from rich biodiversity to the barren, cold land of blizzards we see today, Antarctica provides a dramatic case study of how subtle changes in continental positioning can affect living communities, and how rapidly catastrophic changes can come about. Antarctica has gone from paradise to polar ice in just a few million years, a geological blink of an eye when we consider the real age of Earth. Frozen in Time presents a comprehensive overview of the fossil record of Antarctica framed within its changing environmental settings, providing a window into a past time and environment on the continent. It reconstructs Antarctica’s evolving animal and plant communities as accurately as the fossil record permits. The story of how fossils were first discovered in Antarctica is a triumph of human endeavour. It continues today with modern expeditions going out to remote sites every year to fill in more of the missing parts of the continent’s great jigsaw of life.

What, if anything, is micropaleontology?

Paleobiology ◽  
1981 ◽  
Vol 7 (2) ◽  
pp. 167-199 ◽  
Author(s):  
Jere H. Lipps
Keyword(s):  
Fossil Record ◽  
Biological Properties ◽  
Evolutionary Processes ◽  
New Ideas ◽  
Historic Development ◽  
The Many ◽  
Fossil Records

Micropaleontology is a peculiar subject: it is not easily defined, it focuses on geologic problems, and it ignores fundamental paleontologic and evolutionary questions it could best attack. As a result of its historic development, micropaleontology is directed to the solution of stratigraphic, paleoceanographic and paleoclimatologic problems, but it has seldom addressed paleobiologic or evolutionary ideas. It is a tradition rather than a discipline. The term “micropaleontology” and all it signifies should be abandoned, for it obscures natural relationships, attracts people with geologic rather than biologic approaches, isolates its practitioners in a blanket of systematics, biostratigraphies, and terminologies, and, as a result, discourages outsiders with other viewpoints or contributions from utilizing its fine fossil record. The growth of the field has been exponential in people-power and literature but not in the development of fundamentally new ideas. Micropaleontology has therefore contributed little to recent paleobiologic or evolutionary hypotheses, in spite of the possession by the many organisms relegated to it of biological properties and fossil records which have much potential for the generation and testing of such hypotheses. Microfossil studies have served geology powerfully and they should continue in that role, but they should also be used to fulfill their promise in the interpretation of paleobiogeography, paleoecology, morphology, evolutionary processes and the origin of new groups and ground plans.

scholarly journals Ecogeochemistry potential in deep time biodiversity illustrated using a modern deep-water case study

2016 ◽  
Vol 371 (1691) ◽  
pp. 20150223 ◽  
Author(s):  
Clive N. Trueman ◽  
Ming-Tsung Chung ◽  
Diana Shores
Keyword(s):  
Fossil Record ◽  
Temporal Trends ◽  
Morphological Diversity ◽  
Population Connectivity ◽  
The Body ◽  
Deep Time ◽  
The Common ◽  
Body Fossil ◽  
Methodological Ground

The fossil record provides the only direct evidence of temporal trends in biodiversity over evolutionary timescales. Studies of biodiversity using the fossil record are, however, largely limited to discussions of taxonomic and/or morphological diversity. Behavioural and physiological traits that are likely to be under strong selection are largely obscured from the body fossil record. Similar problems exist in modern ecosystems where animals are difficult to access. In this review, we illustrate some of the common conceptual and methodological ground shared between those studying behavioural ecology in deep time and in inaccessible modern ecosystems. We discuss emerging ecogeochemical methods used to explore population connectivity and genetic drift, life-history traits and field metabolic rate and discuss some of the additional problems associated with applying these methods in deep time.

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