Structure and function of the cassowary's casque and its implications for cassowary history, biology and evolution

@article{Naish2016StructureAF,
  title={Structure and function of the cassowary's casque and its implications for cassowary history, biology and evolution},
  author={Darren Naish and Richard Perron},
  journal={Historical Biology},
  year={2016},
  volume={28},
  pages={507 - 518}
}
Cassowaries (Casuarius) possess a cranial casque, sheathed by keratin and composed of modified cranial bones. We combine data and hypotheses on three areas of cassowary research. First, we present novel observations on casque anatomy. The bony core is fragile, incorporating a mass of trabeculae anteriorly and an empty space posteriorly. Secondly, we use these observations to evaluate hypotheses of casque function. Implications that the casque evolved within the context of activities involving… 
Osteological description of casque ontogeny in the southern cassowary (Casuarius casuarius) using micro‐CT imaging
TLDR
Casque osteology of the southern cassowary (C. casuarius) is clarified by detailing casque anatomy across an extensive growth series for the first time by using micro‐computed tomography imaging to visualize embryonic development and post‐hatching ontogeny through adulthood.
The phylogenetic significance of the morphology of the syrinx, hyoid and larynx, of the southern cassowary, Casuarius casuarius (Aves, Palaeognathae)
TLDR
Syrinx, hyoid and larynx characters of palaeognaths display greater concordance with molecular trees than do other morphological traits, and might therefore be less prone to homoplasy related to flightlessness and gigantism, compared to typical morphological character traits emphasised in previous phylogenetic studies.
REPORT FROM A BOU-FUNDED PROJECT
Cranial ornaments such as keratinous horns and bony casques are commonplace amongst birds and take a variety of diverse forms. Possible functions include display, thermoregulation, vocalisation and
High diversity of the Ganzhou Oviraptorid Fauna increased by a new “cassowary-like” crested species
TLDR
It is hypothesize, based on the inner structure compared to that in modern cassowaries, that the prominent casque of Corythoraptor was a multifunction-structure utilized in display, communication and probably expression of the fitness during mating seasons.
A survey of casques, frontal humps, and other extravagant bony cranial protuberances in birds
TLDR
Bony cranial protuberances are most widespread among galloanserine birds, which is particularly true for helmet-like casques on top of the skull, but their absence in most neoavian taxa is noteworthy and requires future studies to address possible ontogenetic, ecological, or functional constraints on their formation.
Cranial ornamentation in the Late Cretaceous nodosaurid ankylosaur Hungarosaurus
TLDR
New details of the cranial anatomy of the nodosaurid Hungarosaurus from the Santonian of Europe are provided and available evidence indicates that cranial ornamentation forms as a result of the elaboration of individual elements.
Adaptive evolution of a derived radius morphology in manakins (Aves, Pipridae) to support acrobatic display behavior
TLDR
This study provides some of the first insight into the osteological evolution of passerine birds, as well as the way in which opposing selective forces can shape skeletal design in these species.
The tapejarid pterosaur Tupandactylus imperator from Crato Formation and the preservation of cranial integuments
TLDR
The occurrence of casques in pterosaurs is supported by comparative anatomy with the bird galliform Pauxi (Cracidae) and it is discussed on the skull with extravagant cranial crests of Tupandactylus imperator and the significance of the associated soft tissues and other cranial integuments, which indicates an expressive morphological and taxonomic diversity among the tapejarids.
A quantitative comparative analysis of the size of the frontoparietal sinuses and brain in vombatiform marsupials
TLDR
The crania of seven species of extinct and extant vombatiform marsupials were studied using CT scans to provide a volumetric assessment of the endocast and cranial sinuses.
Sex and Ontogenetic Variation in the Crest of Numida meleagris: Implications for Crested Vertebrates
TLDR
It is shown that juveniles have smaller skulls than adults and have smaller, simpler crests that are visible even in very young individuals, and that the overlying keratin does not always mimic the underlying bony crest, which should be considered when reconstructing extinct crested vertebrates.
...
1
2
...

References

SHOWING 1-10 OF 92 REFERENCES
Comparative Anatomy of the External and Middle Ear of Palaeognathous Birds
TLDR
The recesses of the middle ear cavity have been investigated using X-ray computed tomography and it has been shown that three tympanic recesses are a character shared by all birds.
The evolutionary radiation of modern birds (Neornithes): reconciling molecules, morphology and the fossil record
TLDR
Current understanding of the early fossil history of Neornithes is highlighted in conjunction with available phylogenetic resolution for the major extant clades, as well as recent advancements in genetic methods that have constrained time estimates for major evolutionary divergences.
Revision of Dromaius gidju Patterson and Rich, 1987 from Riversleigh, northwestern Queensland, Australia, with a reassessment of its generic position
Dromaiusgid;u Patterson and Rich 1987, from the Miocene Kutjamarpu local fauna of central Australia, was described on the basis of associated hindlimb elements. New hindlimb material from the type
Does mutual sexual selection explain the evolution of head crests in pterosaurs and dinosaurs
TLDR
It is concluded that mutual sexual selection presents a valid hypothesis for the functions of ornithodiran cranial crests and the integration of mutualSexual selection into future studies is critical to the authors' understanding of OrnithodIRan ecology, evolution and particularly questions regarding sexual dimorphism.
The history and significance of the fossil Casuarius lydekkeri
TLDR
In 1891 Lydekker made known the existence of a fossil cassowary of the PJeistocene of New South Wales, Australia, based on a cast presented to the British Museum by the Trustees of the Australian Museum.
Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comparative anatomy. II. Analysis and discussion
TLDR
A phylogenetic (cladistic) analysis of 150 taxa of Neornithes, including exemplars from all non-passeriform families, and subordinal representatives of Passeriformes, confirmed the topology among outgroup Theropoda and achieved robust resolution at virtually all levels of the NeornIthes.
The species recognition hypothesis explains exaggerated structures in non-avialan dinosaurs better than sexual selection does
TLDR
It is shown that there have been historically differing definitions of sexual selection, which have greatly impeded understanding of the whole phenomenon of mate attraction and choice, and it is impossible to accept any hypothesis as the “default” that does not require evidence or testing to establish it.
CHAPTER 7 – The Phylogeny of Ratite Birds: Resolving Conflicts between Molecular and Morphological Data Sets
The chapter attempts to investigate paleognath interrelationships and further augments both morphological and molecular data sets. It describes several new postcranial characters and adds new
The ‘species recognition hypothesis’ does not explain the presence and evolution of exaggerated structures in non‐avialan dinosaurs
TLDR
It is concluded that species recognition was not the evolutionary mechanism most likely to be driving the appearance and persistence of exaggerated structures in non-avialan dinosaurs.
A pygmy cassowary (Casuarius lydekkeri) from late Pleistocene bog deposits at Pureni, Papua New Guinea
Although the present-day bird fauna of New Guinea is one of the richest in the world, its palaeo-history is almost unknown. Fossilised phalanges of a small cassowary have been collected from Pliocene
...
1
2
3
4
5
...