Like Acutiramus, Pterygotus lived in fully marine environments, and its fossils are today recovered associated with common and diverse fossils indicative of such an environment.
Notably, P. barrandei and P. cobbi occur in marine environments associated with fossils of Acutiramus.
Pterygotus was more widespread than Acutiramus and as such many species occur without associated representatives of Acutiramus as well, such as the British P. lightbodyi.
The living environment of P. australis, also marine, was in particularly deep water.
The only known fossil organisms of the same age and place as P. australis are crinoids of the genus Dendrocrinus and Kooptoonocrinus and ophiouroids of the genus Protaster.

The deposits where the holotype specimen of P. kopaninensis was found preserves fossils of many other animals as well.
Among them are trilobites such as Leonaspis, Raphiophorus and a fragmentary harpetid trilobite.
Also preserved are bivalves, such as Cardiola, and graptolites, such as Monograptus.
Pterygotus most typically occurs in ecosystems with diverse eurypterid faunas, P. lanarkensis of the Kip Burn Formation of Scotland occurs together with several other eurypterid genera; Slimonia, Eusarcana, Nanahughmilleria, Parastylonurus, Erettopterus and Carcinosoma.
P. impacatus from Estonia occurs together with genera Erettopterus, Erieopterus, Carcinosoma, Mixopterus, Dolichopterus and Eysyslopterus as well as cephalaspidomorph fishes.
P. monroensis lived alongside Mixopterus, Hughmilleria, Eurypterus and Carcinosoma.
P. nobilis lived alongside representatives of Acutiramus, Erettopterus and Eusarcana as well as with a diverse fauna of conodonts, gastropods, cephalopods, ostracods, malacostracans, trilobites and bivalves and cartilaginous fish Onchus.

In the Early Devonian Dundee Formation of Scotland, fossils of P. anglicus occur together with a wide array of different eurypterids, including Erieopterus, Pagea, Tarsopterella and Stylonurus, as well as acanthodian fish Ischnacanthus and Mesacanthus, shark Climatius and osteostracian fish Cephalaspis.
Fossils of P. carmani of similar age found in the Holland Quarry Shale Formation of Ohio also preserve a diverse Devonian fauna of various eurypterids, such as Dolichopterus, Strobilopterus and Erettopterus, as well as pteraspidomorph fish Allocrytaspis and placoderm fish Aethapsis.
Puncture wounds on fossil poraspid fish attributed to the related pterygotid Jaekelopterus demonstrate that pterygotids would have been capable of preying on armored fish such as pteraspidomorphs and placoderms.
The deposits that yielded the fossils of P. siemiradzkii have also yielded fossils of Eurypterus and several genera of pteraspidomorph fish; Larnovaspis, Phialaspis, Corvaspis and Podolaspis.

Five species of Pterygotus have been discovered in deposits of Silurian age in the Welsh Borderland, P. ludensis, P. arcuatus, P. grandidentatus, P. lightbodyi and P. denticulatus.
The Welsh Borderland preserves one of the more extensive eurypterid faunas known, with the exact genera and species depending on the precise time.
The Wenlock-aged P. grandidentatus occurred together with Mixopterus, P. arcuatus of Middle Ludlow age occurred together with Salteropterus, Erettopterus and Carcinosoma whilst P. lightbodyi and P. denticulatus were contemporaries with each other and species of the genera Erettopterus and Carcinosoma.
P. ludensis, Downtonian in age, occurred together with a diverse array of eurypterids composed of Carcinosoma, Dolichopterus, Erettopterus, Hughmilleria, Parahughmilleria, Eurypterus, Nanahughmilleria, Marsupipterus, Stylonurus, Tarsopterella, Slimonia and Salteropterus.

Sometimes the only known other fossil eurypterids occurring with Pterygotus are also pterygotids.
P. marylandicus occurs together only with Erettopterus.
The dubious P. taurinus from England has been found in deposits that have also yielded the remains of Erettopterus as well as a variety of fish, such as acanthodians, thelodontiforms as well as cephalaspidomorphs Hemicyclaspis and Thyestes.

In some cases, Pterygotus r
Like Acutiramus, Pterygotus lived in fully marine environments, and its fossils are today recovered associated with common and diverse fossils indicative of such an environment. Notably, P. barrandei and P. cobbi occur in marine environments associated with fossils of Acutiramus. Pterygotus was more widespread than Acutiramus and as such many species occur without associated representatives of Acutiramus as well, such as the British P. lightbodyi. The living environment of P. australis, also marine, was in particularly deep water. The only known fossil organisms of the same age and place as P. australis are crinoids of the genus Dendrocrinus and Kooptoonocrinus and ophiouroids of the genus Protaster.
The deposits where the holotype specimen of P. kopaninensis was found preserves fossils of many other animals as well. Among them are trilobites such as Leonaspis, Raphiophorus and a fragmentary harpetid trilobite. Also preserved are bivalves, such as Cardiola, and graptolites, such as Monograptus. Pterygotus most typically occurs in ecosystems with diverse eurypterid faunas, P. lanarkensis of the Kip Burn Formation of Scotland occurs together with several other eurypterid genera; Slimonia, Eusarcana, Nanahughmilleria, Parastylonurus, Erettopterus and Carcinosoma. P. impacatus from Estonia occurs together with genera Erettopterus, Erieopterus, Carcinosoma, Mixopterus, Dolichopterus and Eysyslopterus as well as cephalaspidomorph fishes. P. monroensis lived alongside Mixopterus, Hughmilleria, Eurypterus and Carcinosoma. P. nobilis lived alongside representatives of Acutiramus, Erettopterus and Eusarcana as well as with a diverse fauna of conodonts, gastropods, cephalopods, ostracods, malacostracans, trilobites and bivalves and cartilaginous fish Onchus.
In the Early Devonian Dundee Formation of Scotland, fossils of P. anglicus occur together with a wide array of different eurypterids, including Erieopterus, Pagea, Tarsopterella and Stylonurus, as well as acanthodian fish Ischnacanthus and Mesacanthus, shark Climatius and osteostracian fish Cephalaspis. Fossils of P. carmani of similar age found in the Holland Quarry Shale Formation of Ohio also preserve a diverse Devonian fauna of various eurypterids, such as Dolichopterus, Strobilopterus and Erettopterus, as well as pteraspidomorph fish Allocrytaspis and placoderm fish Aethapsis. Puncture wounds on fossil poraspid fish attributed to the related pterygotid Jaekelopterus demonstrate that pterygotids would have been capable of preying on armored fish such as pteraspidomorphs and placoderms. The deposits that yielded the fossils of P. siemiradzkii have also yielded fossils of Eurypterus and several genera of pteraspidomorph fish; Larnovaspis, Phialaspis, Corvaspis and Podolaspis.
Five species of Pterygotus have been discovered in deposits of Silurian age in the Welsh Borderland, P. ludensis, P. arcuatus, P. grandidentatus, P. lightbodyi and P. denticulatus. The Welsh Borderland preserves one of the more extensive eurypterid faunas known, with the exact genera and species depending on the precise time. The Wenlock-aged P. grandidentatus occurred together with Mixopterus, P. arcuatus of Middle Ludlow age occurred together with Salteropterus, Erettopterus and Carcinosoma whilst P. lightbodyi and P. denticulatus were contemporaries with each other and species of the genera Erettopterus and Carcinosoma. P. ludensis, Downtonian in age, occurred together with a diverse array of eurypterids composed of Carcinosoma, Dolichopterus, Erettopterus, Hughmilleria, Parahughmilleria, Eurypterus, Nanahughmilleria, Marsupipterus, Stylonurus, Tarsopterella, Slimonia and Salteropterus.
Sometimes the only known other fossil eurypterids occurring with Pterygotus are also pterygotids. P. marylandicus occurs together only with Erettopterus. The dubious P. taurinus from England has been found in deposits that have also yielded the remains of Erettopterus as well as a variety of fish, such as acanthodians, thelodontiforms as well as cephalaspidomorphs Hemicyclaspis and Thyestes.
In some cases, Pterygotus r
Pterygotus