UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

x

Rule 13d-1(b)

o

Rule 13d-1(c)

o

Rule 13d-1(d)

CUSIP No. 040049108

1.

Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only)
Vaughan Nelson Investment Management, L.P.   04-3304963

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

o

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
515,925

6.

Shared Voting Power
0

7.

Sole Dispositive Power
515,925

8.

Shared Dispositive Power
499,789

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
1,015,714 shares

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o
Not Applicable

11.

Percent of Class Represented by Amount in Row (9)
6.93%

12.

Type of Reporting Person (See Instructions)
IA

CUSIP No. 040049108

1.

Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only)
Vaughan Nelson Investment Management, Inc. 04-3304959

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

o

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
515,925

6.

Shared Voting Power
0

7.

Sole Dispositive Power
515,925

8.

Shared Dispositive Power
499,789

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
1,015,714 shares

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o
Not Applicable

11.

Percent of Class Represented by Amount in Row (9)
6.93%

12.

Type of Reporting Person (See Instructions)
HC

Item 1.

(a)

Name of Issuer
Arena Resources, Inc.

(b)

Address of Issuer’s Principal Executive Offices
4920 South Lewis Street, Suite 107

Tulsa, OK 74105

Item 2.

(a)

Name of Person Filing
Vaughan Nelson Investment Management, L.P. (“Vaughan Nelson”)

Vaughan Nelson Investment Management, Inc. (“General Partner”)

(b)

Address of Principal Business Office or, if none, Residence
Both Vaughan Nelson and the General Partner maintain their principal offices at:

600 Travis, Suite 6300

Houston, Texas 77002

(c)

Citizenship
Vaughan Nelson is Delaware limited partnership.

The General Partner is a Delaware corporation.

(d)

Title of Class of Securities
Common Stock

(e)

CUSIP Number
040049108

Item 3.

If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

o

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b)

o

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c)

o

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d)

o

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8).

(e)

x

An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);

(f)

o

An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);

(g)

x

A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h)

o

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

o

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

o

Group, in accordance with §240.13d-1(b)(1)(ii)(J).

Item 4.

Ownership

By reason of investment advisory relationships with the person who owns the Shares, Vaughan Nelson may be deemed to be the beneficial owner of the reported shares of the Issuer’s common stock. Vaughan Nelson Investment Management, Inc., as General Partner of Vaughan Nelson, may be deemed the indirect beneficial owner of the reported shares of the Issuer’s common stock. Both Vaughan Nelson and Vaughan Nelson Investment Management, Inc. disclaim beneficial ownership of the reported shares of the Issuer’s common stock.

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a)

Amount beneficially owned:

1,015,714

(b)

Percent of class:   

6.93%

(c)

Number of shares as to which the person has:

(i)

Sole power to vote or to direct the vote   

515,925

(ii)

Shared power to vote or to direct the vote    

0

(iii)

Sole power to dispose or to direct the disposition of   

515,925

(iv)

Shared power to dispose or to direct the disposition of   

499,789

Item 5.

Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following   o.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person

Various persons, as investment advisory clients of Vaughan Nelson,  have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the common stock of the Issuer.  To the knowledge of Vaughan Nelson, no one such person’s interest in the common stock of the Issuer is more than five percent of the total outstanding common stock of the Issuer.

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person

Not Applicable

Item 8.

Identification and Classification of Members of the Group

Not Applicable

Item 9.

Notice of Dissolution of Group

Not Applicable

Item 10.

Certification

Each of the Reporting Persons hereby makes the following certification:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

Vaughan Nelson Investment Management, L.P.

By:

/s/     Richard B. Faig

By:         Richard B. Faig

Its:          Chief Compliance Officer

Vaughan Nelson Investment Management, Inc.

By:

/s/     Richard B. Faig

By:         Richard B. Faig

Its:          Chief Compliance Officer

Vaughan Nelson Investment Management, L.P.

By:

/s/   Richard B. Faig

By:       Richard B. Faig

Its:        Chief Compliance Officer

Vaughan Nelson Investment Management, Inc.

By:

/s/   Richard B. Faig

By:       Richard B. Faig

Its:        Chief Compliance Officer