Standard Event System
The "Standard Event System" to Study Vertebrate Embryos was developed in 2009 to establish a common language in comparative embryology. Homologous developmental characters are defined therein and should be recognisable in all vertebrate embryos. The SES includes a protocol on how to describe and depict vertebrate embryonic characters. The SES was initially developed for external developmental characters of organogenesis, particularly for turtle embryos. However, it is expandable both taxonomically and in regard to anatomical or molecular characters. This article should act as an overview on the species staged with SES and document the expansions of this system. New entries need to be validated based on the citation of scientific publications. The guideline on how to establish new SES-characters and to describe species can be found in the original paper of Werneburg.
SES-characters are used to reconstruct ancestral developmental sequences in evolution such as that of the last common ancestor of placental mammals. Also the plasticity of developmental characters can be documented and analysed.
SES-staged species
Overview on the vertebrate species staged with SES.| Major taxon 1 | Major taxon 2 | Species | Reference |
| Lissamphibia | Caudata | Ambystoma mexicanum | |
| Testudines | Pleurodira | Emydura subglobosa | |
| Testudines | Cryptodira | Graptemys nigrinoda | |
| Testudines | Cryptodira | Kinosternum scorpionoides | |
| Testudines | Cryptodira | Apalone spinifera, Caretta caretta, Carettochelys insculpta, Chelonia mydas, Chelydra serpentina, Chrysemys picta, Dermochelys coriacea, Eretmochelys imbricata, Lepidochelys olivacea, Natator depressus, Pelodiscus sinensis, Testudo hermanni, Trachemys scripta | |
| Crocodilia | Alligatoridae | Alligator mississippiensis | |
| Squamata | Lacertidae | Zootoca vivipara | |
| Squamata | Serpentes | Bothropoides jararaca | |
| Squamata | Gymnophthalmidae | Calyptommatus sinebranchiatus, Nothobachia ablephara | |
| Aves | Galliformes | Gallus gallus | |
| Mammalia | Monotremata | Tachyglossus aculeatus | |
| Mammalia | Monotremata | Ornithorhynchus anatinus | |
| Mammalia | Marsupialia | Didelphis virginiana | |
| Mammalia | Marsupialia | Monodelphis domestica, Sminthopsis macroura, Dasyurus hallucus, Dasyurus viverrinus, Phascolarctos cinereus, Petauroides volans, Trichosurus vulpecula, Bettongia gaimardi, Macropus eugenii | |
| Mammalia | Marsupialia | Caenolestes fuliginosus | |
| Mammalia | Xenarthra | Dasypus hybridus | |
| Mammalia | Xenarthra | Bradypus tridactylus | |
| Mammalia | Afrotheria | Echinops telfairi, Tenrec ecaudatus | |
| Mammalia | Afrotheria | Elephas maximus, Loxodonta africana | |
| Mammalia | Laurasiatheria | Talpa occidentalis, Talpa europaea, Erinaceus europaeus, Erinaceus roumanicus, Suncus murinus, Crocidura russela, Neomys fodiens, Sorex araneus, Pecari tajacu, Sus scrofa domesticus, Rangifer tarandus, Capreolus capreolus, Bos primigenius taurus, Capra aegagrus hircus, Ovis aries, Phocoena phocoena, Delphinus delphis, Stenella longirostris, Stenella attenuata, Hipposideros armiger, Hipposideros pratti, Molossus rufus, Myotis lucifugus, Myotis myotis, Pipistrellus abramus, Scotophilus kuhlii, Miniopterus natalensis, Miniopterus schreibersii, Carollia perspicillata, Equus ferus caballus, Manis javanica, Felis catus, Mustela putorius, Canis lupus familiaris | |
| Mammalia | Boreoeutheria | Oryctolagus cuniculus, Spermophilus citellus, Cavia porcellus, Cricetulus barabensis, Mesocricetus auratus, Myodes glareolus, Meriones unguiculatus, Acomys dimidiatus, Apodemus sylvaticus, Apodemus falvicollis, Apodemus agrarius, Rattus norvegicus, Tupaia javanica, Tupaia belangeri, Galago senegalensis, Nycticebus cougang, Tarsius tarsier, Callithrix jacchus, Erythrocebus patas, Papio cynocephalus, Macaca mulatta, Homo sapiens | |
| Mammalia | Boreoeutheria | Mus musculus |