Functional traits and their potential ecological functions.

Distribution of threat status across anuran families in China, based on the China Biodiversity Red List– Vertebrates Volume (2020).

Each stacked bar represents the proportion of species within a family categorized as Critically Endangered (CR), Endangered (EN), Vulnerable (VU), Near Threatened (NT), or Least Concern (LC). Families are ordered by total number of species.

Regression analysis results of extinction risk for adult and tadpole stages.

For abbreviations of traits, please refer to Table 1. BM, Brownian motion; OU, Ornstein-Uhlenbeck; GLS, generalized least squares; PGLS, phylogenetic generalized least squares; AICc, Akaike Information Criterion corrected for small sample size.

Phylogenetically corrected associations between functional traits and extinction risk in Chinese anurans, separately for (A) adults and (B) tadpoles.

Each dot represents the PGLS regression coefficient (β) for a given trait, with horizontal lines indicating 95% confidence intervals. Traits significantly associated with threat status are marked with asterisks (*p < 0.05; **p < 0.01; ***p < 0.001). For abbreviations of traits, please refer to Table 1. The silhouette images are sourced from phylopic (Minervarya mudduraja by Vijay Karthick; Bufo bufo by Luca Leicht).

Relationships between tadpole and adult size within anuran families.

SVL: snout-vent length; TOL: total length. d: parameter quantifying the rate of return to the optimal value in the Ornstein-Uhlenbeck (OU) evolutionary model, reflecting the strength of phylogenetic signal.

The results of variance inflation factors for adult and tadpole traits.

For abbreviations of traits, please refer to Table 1.

Regression analysis results of extinction risk for adult and tadpole stages (IUCN).

For abbreviations of traits, please refer to Table 1. BM, Brownian motion; OU, Ornstein–Uhlenbeck; GLS, generalized least squares; PGLS, phylogenetic generalized least squares; AICc, Akaike Information Criterion corrected for small sample size.

Data completeness of each trait for (A) adults and (B) tadpoles.

Trait importance (Sum of Akaike Weights) of adult and tadpole traits based on model averaging under the OU evolutionary model using China Biodiversity Red List.

For abbreviations of traits, please refer to Table 1. The silhouette images are sourced from phylopic (Minervarya mudduraja by Vijay Karthick; Bufo bufo by Luca Leicht).

Phylogenetically corrected associations between functional traits and extinction risk in Chinese anurans based on IUCN Red list for (A) adults and (B) tadpoles.

Each dot represents the PGLS regression coefficient (β) for a given trait, with horizontal lines indicating 95% confidence intervals. Traits significantly associated with threat status are marked with asterisks (*p < 0.05; **p < 0.01; ***p < 0.001). For abbreviations of traits, please refer to Table 1. The silhouette images are sourced from phylopic (Minervarya mudduraja by Vijay Karthick; Bufo bufo by Luca Leicht).

Trait importance (sum of Akaike Weights) of adult and tadpole traits based on model averaging under the OU evolutionary model using IUCN Red List.

For abbreviations of traits, please refer to Table 1. The silhouette images are sourced from phylopic (Minervarya mudduraja by Vijay Karthick; Bufo bufo by Luca Leicht).

Violin plots showing the distribution of (A) head length and (B) tympanum diameter across anuran families in China.

Species of the Bombinatoridae lack a tympanum; therefore, they are marked as 0 and are not shown in Figure B. Additionally, because other families also include species without a tympanum, the kernel density estimation produces boundary effects, leading to negative values in the plots. Thus, we truncated the density estimation at the data boundaries during visualization. Each violin plot represents the kernel density estimate of trait values, with the inner boxplot indicating median, interquartile range, and outliers. Traits are standardized relative to snout–vent length.