Stratigraphy and Paleobiology of the Upper Cretaceous-Lower Paleogene Sediments from the Trans-Saharan Seaway in Mali

O’Leary, Maureen A.; Bouaré, Mamadou L.; Claeson, Kerin M.; Heilbronn, Kelly; Hill, Robert V.; McCartney, Jacob A.; Sessa, Jocelyn A.; Sissoko, Famory; Tapanila, Leif; Wheeler, Elisabeth A.; Roberts, Eric M.

doi:10.1206/0003-0090.436.1.1

Cited by 27 publications

(33 citation statements)

References 286 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A possible exception is represented by a single incomplete jaw fragment from the Maastrichtian Ménaka Formation of Mali referred to the genus † Brychaetus (O'Leary et al . 2019), which is known from early Palaeogene marine deposits worldwide (see following subsections).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A Paleocene (Danian) marine osteoglossid (Teleostei, Osteoglossomorpha) from the Nuussuaq Basin of Greenland, with a brief review of Palaeogene marine bonytongue fishes

Capobianco

Foreman

Friedman

2019

Papers in Palaeontology

View full text Add to dashboard Cite

The early Palaeogene represents a key interval in the evolution of modern marine fish faunas. Together with the first appearances of many familiar fish lineages characteristic of contemporary marine environments, early Palaeogene marine deposits worldwide feature the occurrence of osteoglossid bonytongues. Their presence in marine rocks is surprising, given that these fishes are strictly associated with freshwater environments in modern settings and in other parts of the fossil record. Despite its possible relevance to faunal recovery after the Cretaceous–Palaeogene (K–Pg) extinction, this marine osteoglossid radiation is relatively understudied. Here we describe an osteoglossid specimen from marine Danian deposits of western Greenland (Eqalulik Formation, northern Nuussuaq Peninsula). It consists of disarticulated cranial, pectoral and vertebral material belonging to a relatively large‐bodied predator, similar to the widespread †Brychaetus but with some distinctive features. This specimen expands the geographical range of extinct osteoglossids to the Arctic and represents one of the earliest records of this group in marine deposits. We review other fossil occurrences of marine osteoglossids, highlighting temporal and biogeographical patterns that characterize their rise, diversification and sudden disappearance in the middle Eocene. It is likely that the transition from freshwater to marine environments occurred around the K–Pg boundary, possibly related to ecological replacement of predatory fish lineages that went extinct at the end of the Cretaceous. Further study of the Eqalulik Formation fauna could yield additional insight into the consequences of the end‐Cretaceous extinction with regard to marine fish evolution and the assembly of modern marine faunas.

show abstract

Section: Discussionmentioning

confidence: 99%

“…2017), the Tamaguélelt Formation of Mali (Patterson & Longbottom 1989; O'Leary et al . 2019) and the Nanjemoy Formation in Maryland and Virginia, USA (Weems & Horman 1983; Weems 1999). Articulated remains of non‐Eurasian marine fossil osteoglossids are rare.…”

Section: Discussionmentioning

confidence: 99%

A Paleocene (Danian) marine osteoglossid (Teleostei, Osteoglossomorpha) from the Nuussuaq Basin of Greenland, with a brief review of Palaeogene marine bonytongue fishes

Capobianco

Foreman

Friedman

2019

Papers in Palaeontology

View full text Add to dashboard Cite

show abstract

“…Pycnodus maliensis and Pycnodus zeaformis are the two of the latest occurring species, from the Eocene of Tamaguélelt in the Republic of Mali (Longbottom 1984; O'Leary et al . 2019). As with many pycnodonts, the species are defined by the morphology and arrangement of the molariform ‘crushing’ teeth, borne on the vomer and prearticular bones.…”

Section: The Pycnodontsmentioning

confidence: 99%

Unique damage‐related, gap‐filling tooth replacement in pycnodont fishes

Collins

Underwood

2021

Palaeontology

View full text Add to dashboard Cite

Most jawed vertebrates (gnathostomes) replace their teeth throughout life (polyphyodonty) and there is currently great interest in its molecular and cellular basis, particularly in fish. While much has still to be elucidated, it appears that whichever tooth replacement mechanism is used, only one tooth replaces one predecessor, at any one time. Here we present fossil crushing dentitions of two extinct pycnodont fishes, Pycnodus zeaformis and Pycnodus maliensis. Their surface features and x‐ray micro‐CT virtual sections show no evidence of one‐for‐one replacement. Instead, individual large teeth were replaced by multiple small teeth, for which, as far as we could ascertain, there is no known mechanism. This occurred where underlying dentigerous bone was damaged. Small teeth also developed where parts of large teeth had broken off, and in gaps between large teeth created by the geometry of their close alignment in rows. We compared the virtual sections to those of functionally analogous crushing dentitions of three modern fishes. Contrasting greatly to the pycnodonts, each showed an orderly, one‐for‐one replacement, typical of osteichthyans. We propose that the pycnodont specimens exhibit a gap‐filling tooth addition hitherto unseen in gnathostomes, and that the oral epithelium retained an initiatory competence throughout life, with a programming of ‘if a gap exists, fill it’. This would also have facilitated the addition of large teeth in rows, in space provided by ontogenetic growth. We hypothesize that gaps were registered as an absence of pressure at the crushing surface, initiating tooth development, as in the modern cichlid Astatoreochromis alluaudi.

show abstract

“…These new Palaeogene radiations were joined by a handful of late-surviving examples of predatory marine neopterygian lineages that arose in the Mesozoic, all of which (e.g. †serrasalmimid pycnodontiforms [62], †vidalamine amiids [63] and possibly †pachyrhizodontids [64]) appear to have gone extinct by the end of the Eocene. The raptorial stem engraulids †Clupeopsis and †Monosmilus add to this diverse assortment of early Palaeogene nonacanthomorph predators in shallow-water settings (figure 4).…”

Section: Trophic and Environmental Diversification Among Non-acanthommentioning

confidence: 99%

Large-bodied sabre-toothed anchovies reveal unanticipated ecological diversity in early Palaeogene teleosts

et al. 2020

View full text Add to dashboard Cite

Many modern groups of marine fishes first appear in the fossil record during the early Palaeogene (66–40 Ma), including iconic predatory lineages of spiny-rayed fishes that appear to have originated in response to ecological roles left empty after the Cretaceous/Palaeogene extinction. The hypothesis of extinction-mediated ecological release likewise predicts that other fish groups have adopted novel predatory ecologies. Here, we report remarkable trophic innovation in early Palaeogene clupeiforms (herrings and allies), a group whose modern representatives are generally small-bodied planktivores. Two forms, the early Eocene (Ypresian) † Clupeopsis from Belgium and a new genus from the middle Eocene (Lutetian) of Pakistan, bear conspicuous features indicative of predatory ecology, including large size, long gapes and caniniform dentition. Most remarkable is the presence of a single, massive vomerine fang offset from the midline in both. Numerous features of the neurocranium, suspensorium and branchial skeleton place these taxa on the engraulid (anchovy) stem as the earliest known representatives of the clade. The identification of large-bodied, piscivorous anchovies contributes to an emerging picture of a phylogenetically diverse guild of predatory ray-finned fishes in early Palaeogene marine settings, which include completely extinct lineages alongside members of modern marine groups and taxa that are today restricted to freshwater or deep-sea environments.

show abstract

Stratigraphy and Paleobiology of the Upper Cretaceous-Lower Paleogene Sediments from the Trans-Saharan Seaway in Mali

Cited by 27 publications

References 286 publications

A Paleocene (Danian) marine osteoglossid (Teleostei, Osteoglossomorpha) from the Nuussuaq Basin of Greenland, with a brief review of Palaeogene marine bonytongue fishes

A Paleocene (Danian) marine osteoglossid (Teleostei, Osteoglossomorpha) from the Nuussuaq Basin of Greenland, with a brief review of Palaeogene marine bonytongue fishes

Unique damage‐related, gap‐filling tooth replacement in pycnodont fishes

Large-bodied sabre-toothed anchovies reveal unanticipated ecological diversity in early Palaeogene teleosts

Contact Info

Product

Resources

About