Representados aualmente por apenas duas espécies: Latimeria chalumnae e L. menadoensis, os celaca... more Representados aualmente por apenas duas espécies: Latimeria chalumnae e L. menadoensis, os celacantos (Infraordem Actinistia) já foi muito mais numeroso, prolífico desde os tempos de seu surgimento no Devoniano Inferior. Dentro de Actinistia a família Mawsoniidae se destaca por abranger as maiores espécies do grupo, algumas atingindo até três metros de comprimento. A entrada de Mawsoniidae no continente Gondwana se deu durante o Jurássico superior, período o qual é atribuído a espécie Parnaibaia maranhoensis da bacia do Parnaíba (Maranhão). No cretáceo a família se ramificou em dois outros gêneros Mawsonia (com conhecidas ocorrências brasileiras e africanas) e Axelrodichthys (gênero brasileiro com alguns indícios de presença na África). Este trabalho teve por objetivo realizar uma redescrição e comparação de seis espécies do ramo gondwânico da família Mawsoniidae: Parnaibaia maranhoensis, Axelrodichthys araripensis, Mawsonia gigas, M. minor, M. lavocati e M. brasiliensis. Os espécim...
<i>Axelrodichtys</i> is a genus of fossil coelacanth of the family Mawsoniidae with a... more <i>Axelrodichtys</i> is a genus of fossil coelacanth of the family Mawsoniidae with a wide spatial and temporal range, spanning from the Aptian/Albian of Brazil to the Campanian of France. In light of new discoveries in recent years a renewed interest in <i>Axelrodichthys</i> has emerged. Here we offer new insights on the type species – <i>A. araripensis</i> – based on a complete new description of all its morphological characters and a comparative study of several other Mawsoniidae. A relatively large sample composed of 113 specimens of <i>A. araripensis</i> and associated Mawsoniidae species was observed. Among the newly observed features are the broad aspect of premaxillae supporting the anterior opening of the rostral organ; a unique pattern of skull roof ornamentation; the basioccipital; a passage of nerves in the prootic; the passage for the superior ophthalmic nerve; the anocleithrum; and ossified zygal plates. Observation of two juvenile specimens in different growth stages allowed for the inference of negative allometric growth in the epicaudal lobe. Morphological comparisons pointed out that <i>M. lavocati</i> is more closely associated with the <i>Axelrodichthys</i> than with <i>Mawsonia</i>, therefore we included it in the <i>Axelrodichthys</i> genus as <i>A. lavocati.</i>
The Mawsoniidae family includes six genera Chinlea, Diplurus, Trachymetopon, Parnaibaia, Mawsonia... more The Mawsoniidae family includes six genera Chinlea, Diplurus, Trachymetopon, Parnaibaia, Mawsonia and Axelrodichthys with an almost worldwide occurrence ranging from the Triassic to the Late Cretaceous. The genus Mawsonia is widely registered from the Western Gondwana (South America and Africa) and is currently found in layers of continental origin and in association with fresh water ostracods or with a peculiar continental vertebrate fauna. Here we redescribe some nearly complete skeletons of M. gigas. Mawsoniids are extremely common in the Western Gondwana and, yet various specimens from different basins are referred to M. gigas, this type species is still one of the most poorly known species of this family. The redescription of the specimens from Recôncavo Basin confirms its classification as M. gigas, based mainly on the postcranial skeleton.
Mawsoniids are a lineage of extinct fresh/brackish water coelacanth fishes, common in Cretaceous ... more Mawsoniids are a lineage of extinct fresh/brackish water coelacanth fishes, common in Cretaceous Godwanan deposits of South America, North and West Africa and Madagascar. Here we formally describe mawsoniid remains from the fluvio-lacustrine Missao Velha Formation (Lower Cretaceous) of the Araripe Basin, North-East Brazil. The examples from the Missao Velha Formation are here described as Mawsonia cf. gigas , based mainly on elements of the lower jaw and opercular series. The occurrence of M. cf. gigas in the Missao Velha Formation expands the stratigraphic and geographical ranges of the type species.
Abstract Axelrodichtys is a genus of fossil coelacanth of the family Mawsoniidae with a wide spat... more Abstract Axelrodichtys is a genus of fossil coelacanth of the family Mawsoniidae with a wide spatial and temporal range, spanning from the Aptian/Albian of Brazil to the Campanian of France. In light of new discoveries in recent years a renewed interest in Axelrodichthys has emerged. Here we offer new insights on the type species – A. araripensis – based on a complete new description of all its morphological characters and a comparative study of several other Mawsoniidae. A relatively large sample composed of 113 specimens of A. araripensis and associated Mawsoniidae species was observed. Among the newly observed features are the broad aspect of premaxillae supporting the anterior opening of the rostral organ; a unique pattern of skull roof ornamentation; the basioccipital; a passage of nerves in the prootic; the passage for the superior ophthalmic nerve; the anocleithrum; and ossified zygal plates. Observation of two juvenile specimens in different growth stages allowed for the inference of negative allometric growth in the epicaudal lobe. Morphological comparisons pointed out that M. lavocati is more closely associated with the Axelrodichthys than with Mawsonia, therefore we included it in the Axelrodichthys genus as A. lavocati.
Representados aualmente por apenas duas espécies: Latimeria chalumnae e L. menadoensis, os celaca... more Representados aualmente por apenas duas espécies: Latimeria chalumnae e L. menadoensis, os celacantos (Infraordem Actinistia) já foi muito mais numeroso, prolífico desde os tempos de seu surgimento no Devoniano Inferior. Dentro de Actinistia a família Mawsoniidae se destaca por abranger as maiores espécies do grupo, algumas atingindo até três metros de comprimento. A entrada de Mawsoniidae no continente Gondwana se deu durante o Jurássico superior, período o qual é atribuído a espécie Parnaibaia maranhoensis da bacia do Parnaíba (Maranhão). No cretáceo a família se ramificou em dois outros gêneros Mawsonia (com conhecidas ocorrências brasileiras e africanas) e Axelrodichthys (gênero brasileiro com alguns indícios de presença na África). Este trabalho teve por objetivo realizar uma redescrição e comparação de seis espécies do ramo gondwânico da família Mawsoniidae: Parnaibaia maranhoensis, Axelrodichthys araripensis, Mawsonia gigas, M. minor, M. lavocati e M. brasiliensis. Os espécim...
<i>Axelrodichtys</i> is a genus of fossil coelacanth of the family Mawsoniidae with a... more <i>Axelrodichtys</i> is a genus of fossil coelacanth of the family Mawsoniidae with a wide spatial and temporal range, spanning from the Aptian/Albian of Brazil to the Campanian of France. In light of new discoveries in recent years a renewed interest in <i>Axelrodichthys</i> has emerged. Here we offer new insights on the type species – <i>A. araripensis</i> – based on a complete new description of all its morphological characters and a comparative study of several other Mawsoniidae. A relatively large sample composed of 113 specimens of <i>A. araripensis</i> and associated Mawsoniidae species was observed. Among the newly observed features are the broad aspect of premaxillae supporting the anterior opening of the rostral organ; a unique pattern of skull roof ornamentation; the basioccipital; a passage of nerves in the prootic; the passage for the superior ophthalmic nerve; the anocleithrum; and ossified zygal plates. Observation of two juvenile specimens in different growth stages allowed for the inference of negative allometric growth in the epicaudal lobe. Morphological comparisons pointed out that <i>M. lavocati</i> is more closely associated with the <i>Axelrodichthys</i> than with <i>Mawsonia</i>, therefore we included it in the <i>Axelrodichthys</i> genus as <i>A. lavocati.</i>
The Mawsoniidae family includes six genera Chinlea, Diplurus, Trachymetopon, Parnaibaia, Mawsonia... more The Mawsoniidae family includes six genera Chinlea, Diplurus, Trachymetopon, Parnaibaia, Mawsonia and Axelrodichthys with an almost worldwide occurrence ranging from the Triassic to the Late Cretaceous. The genus Mawsonia is widely registered from the Western Gondwana (South America and Africa) and is currently found in layers of continental origin and in association with fresh water ostracods or with a peculiar continental vertebrate fauna. Here we redescribe some nearly complete skeletons of M. gigas. Mawsoniids are extremely common in the Western Gondwana and, yet various specimens from different basins are referred to M. gigas, this type species is still one of the most poorly known species of this family. The redescription of the specimens from Recôncavo Basin confirms its classification as M. gigas, based mainly on the postcranial skeleton.
Mawsoniids are a lineage of extinct fresh/brackish water coelacanth fishes, common in Cretaceous ... more Mawsoniids are a lineage of extinct fresh/brackish water coelacanth fishes, common in Cretaceous Godwanan deposits of South America, North and West Africa and Madagascar. Here we formally describe mawsoniid remains from the fluvio-lacustrine Missao Velha Formation (Lower Cretaceous) of the Araripe Basin, North-East Brazil. The examples from the Missao Velha Formation are here described as Mawsonia cf. gigas , based mainly on elements of the lower jaw and opercular series. The occurrence of M. cf. gigas in the Missao Velha Formation expands the stratigraphic and geographical ranges of the type species.
Abstract Axelrodichtys is a genus of fossil coelacanth of the family Mawsoniidae with a wide spat... more Abstract Axelrodichtys is a genus of fossil coelacanth of the family Mawsoniidae with a wide spatial and temporal range, spanning from the Aptian/Albian of Brazil to the Campanian of France. In light of new discoveries in recent years a renewed interest in Axelrodichthys has emerged. Here we offer new insights on the type species – A. araripensis – based on a complete new description of all its morphological characters and a comparative study of several other Mawsoniidae. A relatively large sample composed of 113 specimens of A. araripensis and associated Mawsoniidae species was observed. Among the newly observed features are the broad aspect of premaxillae supporting the anterior opening of the rostral organ; a unique pattern of skull roof ornamentation; the basioccipital; a passage of nerves in the prootic; the passage for the superior ophthalmic nerve; the anocleithrum; and ossified zygal plates. Observation of two juvenile specimens in different growth stages allowed for the inference of negative allometric growth in the epicaudal lobe. Morphological comparisons pointed out that M. lavocati is more closely associated with the Axelrodichthys than with Mawsonia, therefore we included it in the Axelrodichthys genus as A. lavocati.
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