The oldest record of aquatic amniote congenital scoliosis

Rarity of congenital malformation and deformity in the fossil record of vertebrates - A non-human perspective

OBJECTIVE

A malformed pectoral joint of the middle Devonian antiarch fish Asterolepis ornata is described, and a survey of congenital malformations in the fossil record is provided.

MATERIALS

The specimen of A. ornata (MB.f.73) from Ehrman in Latvia, stored at the Museum für Naturkunde Berlin, Germany.

METHODS

A. ornata was macroscopically and radiologically investigated, and the overview on congenital malformation was based on an extensive literature survey.

RESULTS

In the deformed joint of A. ornata, the articular surfaces and muscle attachment sites are greatly reduced, indicating restricted mobility. Congenital malformations can be found since the middle Silurian and affect all groups of vertebrates, but they are rare. Teeth and the vertebral column are the most commonly affected anatomical regions, and the mechanisms causing these malformations probably remained the same through geological time.

CONCLUSIONS

Micro-CT of the deformed joint shows no disturbance of the normal trabecular pattern and no evidence of trauma or disease, suggesting a congenital hypoplasia, although an acquired deformity cannot be ruled out completely.

SIGNIFICANCE

Congenital malformations, even those that are rare, were part of the common history of vertebrates for more than 400 million years.

LIMITATIONS

Epidemiologic measures like incidence and prevalence usually cannot be applied to define rare diseases in the fossil record.

SUGGESTIONS FOR FURTHER RESEARCH

A broadly based analysis of species of fossil vertebrates with numerus recovered specimens (e.g. many bony fishes, amphibians, certain dinosaurs) might statistically affirm the occurrence of malformations and possible correlations with the paleoenvironment.

New tomographic contribution to characterizing mesosaurid congenital scoliosis

The presence of a pathology in the vertebral column of the early Permian mesosaurid specimen ZPAL R VII/1, being one of the oldest amniotic occurrences of congenital scoliosis caused by a hemivertebra, was recently recognized. Here we provide CT data to further characterize the phenomenon. The affected hemivertebra is wedged (incarcerated) between the preceding and succeeding vertebrae. The neural canal is misshapen but continuous and the number of dorsal ribs on each side of the specimen corresponds with the number of the vertebrae, documenting its congenital (homeobox-related) derivation.

Tuberculosis-like respiratory infection in 245-million-year-old marine reptile suggested by bone pathologies

An absence of ancient archaeological and palaeontological evidence of pneumonia contrasts with its recognition in the more recent archaeological record. We document an apparent infection-mediated periosteal reaction affecting the dorsal ribs in a Middle Triassic eosauropterygian historically referred to as 'Proneusticosaurus' silesiacus. High-resolution X-ray microtomography and histological studies of the pathologically altered ribs revealed the presence of a continuous solid periosteal reaction with multiple superficial blebs (protrusions) on the visceral surfaces of several ribs. Increased vascularization and uneven lines of arrested growth document that the pathology was the result of a multi-seasonal disease. While visceral surface localization of this periosteal reaction represents the earliest identified evidence for pneumonia, the blebs may have an additional implication: they have only been previously recognized in humans with tuberculosis (TB). Along with this diagnosis is the presence of focal vertebral erosions, parsimoniously compared to vertebral manifestation of TB in humans.