scholarly journals Macroevolutionary analysis of the tempo of diversification in snappers and fusiliers (Percomorpha: Lutjanidae)

2017 ◽  
Vol 147 (1) ◽  
Author(s):  
Bruno Frédérich ◽  
Francesco Santini

The percomorph fish family Lutjanidae (snappers and fusiliers) includes about 135 reef-dwelling species, mainly confined to tropical and subtropical marine waters. The great majority of snappers are active predators feeding on fishes or crustaceans, even though some species, including the fusiliers (Caesioninae), have evolved zooplanktivory. Lutjanids show a great diversity of habitat preferences, based on depth segregation and distribution across reef and associated habitats (e.g., mangroves, seagrass beds, estuaries). In spite of their great ecological and economic importance little is known about the tempo of evolution in this group. The present study provides the most comprehensive molecular phylogeny to date for lutjanids, including 70% of extant species and 19 of the 21 currently described genera. We time-calibrated our molecular tree using the oldest described lutjanid fossils, and show how this group most likely originated during the Late Cretaceous or Early Paleocene. Lutjanids experienced a significant radiation during the Late Eocene and Early Oligocene, in contrast to a pattern of Late Oligocene/Miocene radiation observed in many other reef-associated groups. The time-tree allows us to investigate the tempo of diversification, and our results suggest a variation in the rate of speciation during the evolution of the major clade formed by “lutjanins and caesionins”. Variation in diet and life history strategies could explain this clade-specific dynamic, although future phylogenetic comparative studies combining additional ecological and morphological data are needed to test this hypothesis.

1998 ◽  
Vol 11 (6) ◽  
pp. 711 ◽  
Author(s):  
Robert S. Hill ◽  
Leonie J. Scriven

A re-investigation of macrofossils previously referred to the extantpodocarpaceous genus Falcatifolium Laubenfels shows thatno records can be sustained. Falcatifolium australisD.R.Greenwood from Middle Eocene sediments in Victoria bears littleresemblance to extant species in the genus and is transferred to the newfossil genus Sigmaphyllum R.S.Hill & L.J.Scriven.Specimens from Early Oligocene sediments in Tasmania previously assigned toFalcatifolium are described as a second species ofSigmaphyllum, S. tasmanensisR.S.Hill & L.J.Scriven, and specimens from mid to late Eocene sediments inTasmania previously assigned to Falcatifolium do notbelong to that genus, although their true generic affinities are uncertain.Dispersed cuticle specimens from Late Eocene–Oligocene sediments inSouth Australia referred to Falcatifolium are notreliable records of the genus and require further investigation. However,Dacrycarpus eocenica D.R.Greenwood, from Middle Eocenesediments in Victoria is transferred to Falcatifolium,and is similar to the extant species F. angustumLaubenfels, which has a leaf morphology unusual for the genus.Falcatifolium eocenica (D.R.Greenwood) R.S.Hill & L.J.Scriven is the only reliable record of the genus in the Australian fossilrecord to date.


2019 ◽  
Author(s):  
Andrew C. Rozefelds ◽  
Mary E. Dettmann ◽  
Anita K. Milroy ◽  
Andrew Hammond ◽  
H. Trevor Clifford ◽  
...  

A new fossil flora from central Queensland, of late Eocene or early Oligocene age, has yielded a diverse assemblage of flowering plants and ferns, including the first evidence of horsetails (Equisetum L.) from the Cenozoic of Australia. The fossils assigned to Equisetum are based on a stem fragment, 2–3mm in diameter, and spreading leaf sheath and diaphragm. The leaf sheath is interpreted to consist of ~24–30 leaves. The spatial arrangement of regularly arranged depressions in a section of the outer cortex is interpreted as evidence of the leaf vascular traces, and indicates a similar number of vascular traces. This specimen provides the youngest evidence of the genus from Australia and indicates that Equisetum survived for at least another 50 million years after it was thought to be extinct in Australia. Whereas molecular data for extant species of Equisetum collectively suggest a comparatively recent origin and radiation, the fossil record of the genus indicates a significantly longer and more complex history. Fossils, such as the new specimen from Makowata, Queensland, will, therefore, play a key role in understanding the history and past distribution of Equisetum in Australia. A key challenge is to assemble and characterise the morphological traits of these living and fossil plants to better understand the origins, history and radiation of this remarkable group of euphyllophytes.


2013 ◽  
Vol 87 (5) ◽  
pp. 826-841 ◽  
Author(s):  
Richard L. Squires

The west coast of North America record of the shallow-marine stromboid gastropod genusRimellaAgassiz, 1841 is restudied for the first time in 90 years. This genus comprises a small group of Paleogene gastropods characterized by having an ornamented fusiform shell, a posterior canal ascending the spire, and simple (non-flared) outer lip.Rimella, whose familial ranking has been inconsistent, is placed here in family Rostellariidae Gabb, 1868, subfamily Rimellinae Stewart, 1927.EctinochilusCossmann, 1889;MacilentosClark and Palmer, 1923;VaderosClark and Palmer, 1923; andCowlitziaClark and Palmer, 1923 are recognized here as junior synonyms ofRimella. Four species are recognized from the west coast of North America: early to middle EoceneRimella macilentaWhite, 1889; early EoceneRimella oregonensisTurner, 1938; middle to late EoceneRimella supraplicata(Gabb, 1864) new combination, of whichRostellaria canaliferGabb, 1864,Cowlitizia washingtonensisClark and Palmer, 1923, andCowlitzia problematicaHanna, 1927 are recognized here as junior synonyms; and late EoceneRimella elongataWeaver, 1912.Rimellawas a warm-water gastropod whose earliest known record is of early Paleocene (Danian) age in Pakistan. Other than the west coast of North America,Rimellais found in Eocene strata in western Europe, Turkey, Egypt, Pakistan, southeastern United States, Panama, Peru, and, to a lesser degree, in Trinidad, Columbia, Java, and New Zealand. Global cooling near the end of the Eocene greatly diminished the genus. Its youngest known occurrences are of early Oligocene age in Germany, Italy, England, and Peru.


2021 ◽  
pp. 1-15
Author(s):  
Juan López-Gappa ◽  
Leandro M. Pérez ◽  
Ana C.S. Almeida ◽  
Débora Iturra ◽  
Dennis P. Gordon ◽  
...  

Abstract Bryozoans with calcified frontal shields formed by the fusion of costae, collectively constituting a spinocyst, are traditionally assigned to the family Cribrilinidae. Today, this family is regarded as nonmonophyletic. In the Argentine Cenozoic, cribrilinids were until recently represented by only two fossil species from the Paleocene of Patagonia. This study describes the first fossil representatives of Jolietina and Parafigularia: J. victoria n. sp. and P. pigafettai n. sp., respectively. A fossil species of Figularia, F. elcanoi n. sp., is also described. The material comes from the early Miocene of the Monte León and Chenque formations (Patagonia, Argentina). For comparison, we also provide redescriptions of the remaining extant species of Jolietina: J. latimarginata (Busk, 1884) and J. pulchra Canu and Bassler, 1928a. The systematic position of some species previously assigned to Figularia is here discussed. Costafigularia n. gen. is erected, with Figularia pulcherrima Tilbrook, Hayward, and Gordon, 2001 as type species. Two species previously assigned to Figularia are here transferred to Costafigularia, resulting in C. jucunda n. comb. and C. tahitiensis n. comb. One species of Figularia is reassigned to Vitrimurella, resulting in V. ampla n. comb. The family Vitrimurellidae is here reassigned to the superfamily Cribrilinoidea. The subgenus Juxtacribrilina is elevated to genus rank. Inferusia is regarded as a subjective synonym of Parafigularia. Parafigularia darwini Moyano, 2011 is synonymized with I. taylori Kuklinski and Barnes, 2009, resulting in Parafigularia taylori n. comb. Morphological data suggest that these genera comprise different lineages, and a discussion on the disparities among cribrilinid (sensu lato) spinocysts is provided. UUID: http://zoobank.org/215957d3-064b-47e2-9090-d0309f6c9cd8


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12074
Author(s):  
Shorouq F. Al-Ashqar ◽  
Erik R. Seiffert ◽  
Dorien de Vries ◽  
Sanaa El-Sayed ◽  
Mohamed S. Antar ◽  
...  

Background The rich rodent assemblages from the Eocene–Oligocene deposits of the Jebel Qatrani Formation (Fayum Depression, Egypt) have important implications for our understanding of the origin and paleobiogeography of Hystricognathi, a diverse clade that is now represented by the Afro-Asiatic Hystricidae, New World Caviomorpha, and African Phiomorpha. Methods Here we present previously undescribed material of the enigmatic hystricognath clade Phiocricetomyinae, from two stratigraphic levels in the lower sequence of the Jebel Qatrani Formation—a new genus and species (Qatranimys safroutus) from the latest Eocene Locality 41 (~34 Ma, the oldest and most productive quarry in the formation) and additional material of Talahphiomys lavocati from that species’ type locality, early Oligocene Quarry E (~31–33.2 Ma). Results The multiple specimens of Qatranimys safroutus from L-41 document almost the entire lower and upper dentition, as well as mandibular fragments and the first cranial remains known for a derived phiocricetomyine. Specimens from Quarry E allow us to expand comparisons with specimens from Libya (late Eocene of Dur at-Talah and early Oligocene of Zallah Oasis) that have been placed in T. lavocati, and we show that the Dur at-Talah and Zallah specimens do not pertain to this species. These observations leave the Fayum Quarry E as the only locality where T. lavocati occurs.


2015 ◽  
Vol 11 (4) ◽  
pp. 2977-3018 ◽  
Author(s):  
K. M. Pascher ◽  
C. J. Hollis ◽  
S. M. Bohaty ◽  
G. Cortese ◽  
R. M. McKay

Abstract. The Eocene was characterised by "greenhouse" climate conditions that were gradually terminated by a long-term cooling trend through the middle and late Eocene. This long-term trend was determined by several large-scale climate perturbations that culminated in a shift to "ice-house" climates at the Eocene–Oligocene Transition. Geochemical and micropaleontological proxies suggest that tropical-to-subtropical sea-surface temperatures persisted into the late Eocene in the high-latitude Southwest Pacific Ocean. Here, we present radiolarian microfossil assemblage and foraminiferal oxygen and carbon stable isotope data from Deep Sea Drilling Project (DSDP) Sites 277, 280, 281 and 283 from the middle Eocene to early Oligocene (~ 40–33 Ma) to identify oceanographic changes in the Southwest Pacific across this major transition in Earth's climate history. The Middle Eocene Climatic Optimum at ~ 40 Ma is characterised by a negative shift in foraminiferal oxygen isotope values and a radiolarian assemblage consisting of about 5 % of low latitude taxa Amphicraspedum prolixum group and Amphymenium murrayanum. In the early late Eocene at ~ 37 Ma, a positive oxygen isotope shift can be correlated to the Priabonian Oxygen Isotope Maximum (PrOM) event – a short-lived cooling event recognized throughout the Southern Ocean. Radiolarian abundance, diversity, and preservation increase during the middle of this event at Site 277 at the same time as diatoms. The PrOM and latest Eocene radiolarian assemblages are characterised by abundant high-latitude taxa. These high-latitude taxa also increase in abundance during the late Eocene and early Oligocene at DSDP Sites 280, 281 and 283 and are associated with very high diatom abundance. We therefore infer a~northward expansion of high-latitude radiolarian taxa onto the Campbell Plateau towards the end of the late Eocene. In the early Oligocene (~ 33 Ma) there is an overall decrease in radiolarian abundance and diversity at Site 277, and diatoms are absent. These data indicate that, once the Tasman Gateway was fully open in the early Oligocene, a frontal system similar to the present day was established, with nutrient-depleted subantarctic waters bathing the area around DSDP Site 277, resulting in a more oligotrophic siliceous plankton assemblage.


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