School of Earth Sciences and Key Laboratory of Mineral Resources in Western China (Gansu Province), Lanzhou University, Lanzhou 730000, People's Republic of China.
Laboratorio de Morfología Evolutiva y Paleobiología de Vertebrados, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EGA, Argentina.
Proc Biol Sci. 2024 Feb 14;291(2016):20232320. doi: 10.1098/rspb.2023.2320. Epub 2024 Feb 7.
Mesozoic fossils of frogs are rare in the palaeontological record, particularly those exhibiting soft tissues that offer limited insights into early life-history characteristics. Here we report on a skeletally immature frog from the Lower Cretaceous of northwest China, with egg masses in the body and eggs in the oviduct, indicative of a gravid female. CT reconstruction of the specimen allows referral to and we assign it as a paratype complementing the diagnosis of the type species The new fossil, which might represent a younger individual than the holotype of , shows that sexual maturation occurred before full adulthood in this frog and provides evidence of death linked to mating behaviour. We also discuss other potential sources of variation and life-history traits of . The new finding represents the oldest Early Cretaceous frog preserving eggs and provides a glimpse into ancient anuran development during Mesozoic times.
中生代蛙类化石在古生物学记录中较为罕见,特别是那些能展示软组织的化石,它们为了解早期生活史特征提供了有限的线索。本文报道了一件产自中国西北部早白垩世的骨骼尚未完全成熟的蛙类化石,其体内保存有卵块,输卵管内保存有卵,表明这是一只怀孕的雌性个体。通过对标本的 CT 重建,我们将其鉴定为补充模式种 诊断特征的副型标本。新化石可能代表比 模式种 更为年轻的个体,表明在这种蛙类中,性成熟发生在完全成年之前,并提供了与交配行为相关的死亡证据。我们还讨论了其他潜在的变异来源和 生活史特征。这一新发现代表了保存有卵的最古老的早白垩世蛙类化石,为中生代时期古两栖类的发育提供了一个早期的 glimpse。