Earth’s Original Land Tree Plant

Was the Calamite the first tree like plant to grow on land? Many scientists believe so. It grew as high as 100 feet, towering above its counterparts in the earlier period of its long lifespan which began during the Devonian Period some 400 million years ago. The trunk was a woody hollow tube lacking true bark, like modern trees. The leaves were primitive and needle like, arranged in whorls. The Calamite thrived in hot swampy tropics, especially during the Pennsylvanian Period around 300 mya. Many of their fossils are found worldwide including, USA, China, Canada, South America and Europe. These fossils were found in Sebastian County, Arkansas in an old coal strip mine in 1993 by Michael A. Whitkanack who donated them to my classroom. They are actually the imprints of the Calamite’s leafs and stems which scientists refer to as trace fossils.

Annularia Leaf Imprint from Calamite Tree

Calamite Stem

Internal and External Mold of Calamite Stem



Calamite (Earth’s First Tree Like Land Plant)


Scientific Name: Calamite Common Name: Horsetail / Wiskfern

Kingdom: Plantae

Division: Pteridophyta (Ferns, reproduce by spores)

Class: Sphenopsida or Equisetopsida (means ribbed, vertical jointed stem; bamboo like in appearance)

Order: Equisetales

Family: Calamitaceae

Genus:  (STEM) Calamite (LEAF) Annularia


Special Note: The Calamine may look familiar to some as there modern descendants are horsetails growing only a few feet tall in open fields and edges of wooded areas.


Equisetum is a living fossil as it is the only living genus of the entire class of Equisetopsida, which for over one hundred million years was much more diverse and dominated the understory of the late Paleozoic forests. They were related to the Calamites of which decomposed into layers upon layers buried in abundance in coal deposits from the Carboniferous period.


Comparing Neuropteris and Pecopteris Fossil Leaves and Their Trees, Medullosa and Psaronius

Neuropteris Leaf Imprint

One way to tell the difference between Neuropteris and Pecopteris leaf imprints is by examining the mid-vein of their leaflets. In Neuropteris, the vein stops midway up the leaflet and splits into several veins, whereas the mid-vein in Pecopteris extends up to the tip. Neuropteris leaflets are usually blunt tipped and are attached by a single stem as opposed by the entire base, like Pecopteris. Also, Neuropteris has an overall heartshape.

Click on the image to enlarge and examine closely the details of the leaflets.


Neuropteris became extinct over 200 million years ago. It thrived in the tropics of the Carboniferous Era between the Mississipian Period,350 mya, and the Permian Period, 225 mya. It grew on the seed fern tree called Medullosa, an ancestor of the flowering plant group.  They flourished in hot swamps, a climate which dominated much of the Earth at the time. When Earth’s climate turned colder, it contributed to their final disappearance.


Kingdom: Plantae

Division: Tracheophyta (vascular plants with system of transporting nutrients and liquids)

Class: Gymnosperm (means bare seeds – today’s examples i.e. conifers, cyads, ginkgo)

Order: Pteridospermales (extinct group of seed ferns which bore seeds on leaves)

Family: Medullosales (plants with complex pollen organs and large fronds)

Genera: Neuropteris (given name of foliage)


Medullosa Fern Tree




Explanation of Pecopteris on next page under Category Section of Plant/Tree Fossils


Pecopteris Leaf of Seed Fern Tree

Fern leaves called Pecopteris grew abundantly in the coal swamps of the Carboniferous Period. These leaves dropped off of a 35 foot fern tree  called “Psaronius“, one of the most common Paleozoic types. With its sparse and expansive branches, it resembled the modern day palm tree. It produced as many as 7000 spores on the underside of its leaves. These samples are well preserved in gray coal shale as many Carboniferous leaf fossils. Click on the image to examine closer the difference from the Neuropteris leaves shown on the page above. If you’ll recall the differences: in Neuropteris, the mid-vein stops midway up the leaflet and splits into several veins, whereas the mid-vein in Pecopteris extends up to the tip. Neuropteris leaflets are usually blunt tipped and are attached by a single stem as opposed by the entire base, like Pecopteris.

What makes Pecopteris so special? One way is in its name which was derived from the Greek word meaning, to comb. You can observe in the photo how the arrangement of its leaflets resemble that of a comb. Also, the large fronds produced on Psaronius fern tree cloaked the ancient forest floor in deep shade. The generous shade from both Psaronius and Medullosa fern tress protected the ancient creatures below from the strong ultra violet rays of the sun. Also,the shedding and decomposing of leaves created more layers of soil for roots to extend deeper and deeper alleviating the need for trees to be near water pools. Trees were then able to spread further inland. Yet another benefit was that the leaves fed inland water sources cultivating more fresh water fish varieties. But this fantastic fossil is most special to me because I inherited from my late  father-in-law, Joseph Mirto II. It was found in Johnstown, Pennsylvania.


Kingdom: Plantae

Division: Pteridophtya (meaning vascular plant with transport system for nutrients and fluids)

Class: Filicopsida (Ferns which reproduce with spores)

Order: Marattiales (primitive ferns)

Family: Marattiaceae

Genus: Pecopteris


Psaronius Fern Tree


Botanical Name: Psaronius Common Name: Fern Tree

Kingdom: Plantae

Division: Tracheophyta (meaning vascular plant with transport system for nutrients and fluids)

Class: Marattiopsida (distinguished by massive roots and largest fronds of all fern trees)

Order: Marattiales (primitive ferns)

Family: Psaronlaceae

Genus: Psaronius Species:   magnificus

Lepidodendron & Sigillaria Trees

Lepidodendron Tree Root

The fossil to the right is a section from the root of a 100 foot tree which originated over 400 million years ago. It contains deeply pitted circular patterns, but its tree trunk differed having deeply grooved diamond patterns. It’s a very dense heavy fossil of petrified wood. Petrified wood forms when plant material is buried by sediment and protected from decay caused by oxygen and organisms. Then, groundwater rich in dissolved solids flows through the sediment, replacing the original plant material with silica, calcite, pyrite, iron or another inorganic material such as opal. This was a common occurrence in the swamp forests of the Carboniferous Period from about 360 to 300 million years ago during the late Paleozoic Era.

Click the images to enlarge for clear details, then arrow back to explore more info about these amazing original plants.

Sigillaria & Lepidodendron Tree Leaves


The fossil to the left shows the leaves of these giant Lycopod trees such as Sigllaria and Lepidodendron preserved in coal shale. Their trunks were topped with these plumes of long, grass like leaves; in some cases resembling a bottle brush. Lycopods, such as these, had a relatively short life cycle growing rapidly and reaching heights up to 130 feet. They generated tremendous amounts of decaying peat, which after millions of years became coal and fueled the Industrial Revolution. More importantly, their decaying matter helped revolutionize Earth’s emerging forests by creating soil for trees to develop deeper root systems. This enabled new tree varieties to spread further inland without relying solely on wet or swampy habitats.


Lepdidodendron Scale Tree



Sigillaria Scale Tree


Botanical Names:  Sigillaria and Lepidodendron

Common Name: Scale Tree 

Kingdom: Plantae

Division: Lycopod-iophyta (oldest vascular plant group, reproduced by releasing spores)

Class: Isoetopsida (plants with hollow quill-like leaves spirally arranged on a single, unbranched vein) ie quillworts, scale trees, spike moss)

Order: Lepidondrales (primitive vascular tree-like plants related to lycopods which are loosely grouped with ferns)

Family: Lepidodencraceae (has arrangement of spores on cones born on the shoots)

Genera:  Sigillaria (possess deep lace pattern on trunk with bottle brush crown of leaves) Lepidodendron (possess deep diamond pattern on trunk with plume of grassy leaves on crown. Roots lack diamond pattern.