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.

中文翻译：

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脊椎动物化石记录中罕见的先天畸形和畸形——非人类视角

客观的

描述了中泥盆纪反弓鱼Asterolepis ornata的畸形胸关节，并提供了化石记录中先天性畸形的调查。

材料

来自拉脱维亚 Ehrman的A. ornata (MB.f.73)标本，保存在德国柏林自然博物馆。

方法

A. ornata进行了宏观和放射学研究，先天性畸形的概述基于广泛的文献调查。

结果

在A. ornata的变形关节中，关节面和肌肉附着部位大大减少，表明活动受限。先天性畸形自中志留纪以来可见，影响所有脊椎动物群，但很少见。牙齿和脊柱是最常受影响的解剖区域，导致这些畸形的机制可能在整个地质时期都保持不变。

结论

变形关节的显微 CT 显示正常小梁模式没有紊乱，也没有外伤或疾病的证据，表明先天性发育不全，尽管不能完全排除后天畸形。

意义

先天性畸形，即使是罕见的畸形，也是 4 亿多年前脊椎动物共同历史的一部分。

限制

发病率和流行率等流行病学指标通常不能用于定义化石记录中的罕见疾病。

进一步研究的建议

对具有大量回收标本的脊椎动物化石物种（例如许多硬骨鱼、两栖动物、某些恐龙）进行广泛的分析，可能会在统计上证实畸形的发生以及可能与古环境的相关性。