Hyloidea

**Hyloidea** is a superfamily of frogs. 54% of all living frog and toad species are in Hyloidea. The superfamily Hyloidea started when the ancestor of all its frogs and toads evolved differently from the other animals in the suborder Neobatrachia. This happened at about the same time as the Cretaceous-Paleogene extinction 66 million years ago. Scientists have found some fossils from this time but not enough to tell how this event affected these animals. After this extinction event, more forests grew, so the frogs may have changed so they could climb and live in trees.

Hyloidea has many subgroups:
- Alsodidae  - (26 species)
- Batrachylidae  - (14 species)
- Bufonidae - **true toads** (700 species)
- Brachycephaloides
    - Brachycephalidae  - **saddleback toads**, **flea toads** and **big-headed frogs** (70 species)
    - Craugastoridae  - **fleshbelly frogs** (822 species)
    - Eleutherodactylidae - **robber frogs** (223 species)
- Centrolenids
    - Allophrynidae  - **Tukeit Hill frogs** (3 species)
    - Centrolenidae  - **glass frogs** (155 species)
- Ceratophryidae  - **common horned frogs** (12 species)
- Cycloramphidae  - **glass frogs** (36 species)
- Dendrobatoidea
    - Dendrobatidae  - **poison frogs** (194 species)
    - Aromobatidae   - **cryptic forest frogs** (121 species)
- Hemiphractidae  - (112 species)
- Hylidae  - **treefrogs** (711 species)
- Hylodidae  - (47 species)
- Leptodactylidae  - **southern frogs** (206 species)
- Pelodryadidae <small>Günther, 1858</small> - **Australian treefrogs** (215 species)
- Phyllomedusidae <small>Gunther, 1858</small> - **leaf frogs** (66 species)
- Odontophrynidae  - (53 species)
- Rhinodermatidae  - **Darwin's frogs** or **mouth-brooding frogs** (3  species)
- Telmatobiidae  - **water frogs** (63 species)

## Shared Characteristics of Hyloidea

Hyloidea is the largest superfamily of anurans due to scientists placing frogs into this family when the relationships to others are unknown. Therefore, Hyloidea has the highest species diversity. Hyloidea are all tailless, have shortened bodies, large mouths and muscular hind legs. Most anurans in the superfamily have a lateral‐bender which is a type of pelvis morphology found in walking, hopping and burrowing frogs. Some species that appear later in the taxon have a sagittal‐hinge pelvis found in aquatic frogs as well as walking, hopping and burrowing frogs  and some have a fore–aft slider pelvis found in terrestrial frogs. Hyloidea anurans lack ribs, have complex mouthparts, and their pectoral girdle can be arciferal or firmisternal. They reproduce via axillary amplexus, and their larvae usually have a single spiracle. The average snout-vent length (SVL) of Hyloidea species vary widely, from 10 mm in one species of _Diasporus_ to 320 mm in female _Calyptocephalella gayi_.

## Phylogenic relationships

Anuran animals, frogs and toads, look alike from the outside, so scientists cannot always tell them apart by looking at their morphological characteristics. They use DNA testing to tell which species are related to each other and how. ML analysis and Bayesian analysis are two important ways to do this.  Scientists used them with a nuclear marker toolkit to look at the relationships inside the superfamily Hyloidea on a molecular level.  As they tested 55 relationships of the Hyloidea and was found that 53 out of the 55 previously established nodes on the phylogenetic tree were supported by this DNA testing.

## Distribution

Scientists say the first Hyloidea animals evolved on the Gondwanan supercontinent in what is now southern South America, then spread throughout the world. Today, they live on every continent except Antarctica. In 2020, scientists found a fossilized animal that was roughly 40 million year old. The animal was from the hyloid family Calyptocephalellidae, and the fossil was found on Seymour Island in the Antarctic Peninsula. The distribution of Hyloidea species is highly correlated with climate, with most species found in areas with higher annual mean temperatures.

## Conservation

As of February 2021, the IUCN Red List named 361 of the species in Hyloidea as critically endangered (11.4%), 475 as endangered (15%), and 310 as vulnerable (9.8%).  There are 3161 species in Hyloidea. One of the most important reasons Hyloidea species are dying is because human beings build farms and other things in the places where they live.  This is called habitat loss.